Employee Calling in Sick on Declined Holiday in 2026

Employers frequently face situations where an employee’s request for annual leave has been refused for legitimate business reasons, only for that same employee to then call in sick on the day they wanted off. From an operational perspective, this feels suspicious. From a legal perspective, it is one of the easiest scenarios in which employers can expose themselves to unnecessary risk if they act on instinct rather than evidence.

UK employment law draws a clear distinction between sickness absence and annual leave. One is a statutory protection linked to health and safety and pay rights. The other is a permission-based entitlement subject to employer control. When those two regimes collide, particularly where there is suspicion of dishonesty, employers must navigate carefully. Acting too aggressively can trigger unfair dismissal, discrimination or unlawful deduction claims. Failing to act at all can undermine absence management and operational discipline.

This is not an academic issue. Calling in sick on a declined holiday is one of the most common flashpoints for grievances, disciplinary disputes and tribunal claims because it sits in a grey area between genuine illness, suspected misconduct and business frustration. The governing framework will typically include the Employment Rights Act 1996, the Working Time Regulations 1998 and (where relevant) the Equality Act 2010, alongside statutory sick pay rules and the ACAS Code on disciplinary and grievance procedures.

What this article is about: This guide provides a structured, employer-focused analysis of how UK employment law applies when an employee calls in sick after a holiday request has been declined. It explains what the law requires, what employers must decide at each stage, and how to manage suspicion, evidence, pay and disciplinary risk without breaching statutory duties or exposing the business to avoidable claims. The focus throughout is on defensible decision-making, not assumptions.

Section A: Can an employee lawfully call in sick after a holiday request is refused?

If an employee is genuinely unwell or injured, they can lawfully call in sick after a holiday request has been refused. The timing of the sickness, even where it coincides exactly with the declined holiday, does not remove the employee’s legal protection. From an employer compliance perspective, sickness absence is not permission-based in the way annual leave is. It arises from incapacity to work, not from employer approval.

1. The legal starting point employers must understand

This distinction matters. Employers often assume that because they have lawfully refused holiday, any subsequent absence on that day must be unauthorised. That assumption is legally unsafe. Sickness absence is protected by statute and supported by pay entitlements such as Statutory Sick Pay, subject to eligibility. It does not become misconduct simply because it is inconvenient or poorly timed.

For wider context on handling attendance issues lawfully and consistently, see our guidance on sickness absence and absence management.

2. Why suspicion alone is not enough

From an employer’s perspective, the coincidence is obvious. From a tribunal’s perspective, coincidence is not proof. Employment law requires employers to separate suspicion from evidence. An employee who is genuinely unfit for work remains entitled to be absent, regardless of how unfortunate the timing appears.

Crucially, the law does not require an employee to “prove” they are sick on day one. For absences of seven calendar days or fewer, self-certification applies. This means the employer must initially accept the explanation unless there is a separate breach, such as failure to follow sickness reporting procedures. For details, see self-certification rules.

3. What employers must do at this stage

At this initial point, the employer’s obligations are limited but important. Employers should:

• treat the absence as sickness unless there is objective evidence to the contrary
• apply sickness reporting and notification rules consistently
• avoid classifying the absence as unauthorised without evidence of dishonesty or non-compliance with notification requirements
• avoid any immediate disciplinary response based solely on timing

The correct legal position is to record the absence as sickness, not misconduct, while preserving the employer’s ability to investigate later if concerns remain.

4. What happens if employers get this wrong

Misclassifying sickness absence at this early stage is one of the most common and costly errors employers make. Treating the absence as unauthorised, withholding pay, or issuing warnings without evidence can lead to unlawful deduction of wages allegations, breach of the implied duty of mutual trust and confidence and escalation into grievance. Once an employer has jumped to conclusions, it becomes significantly harder to defend later action, even if further evidence emerges.

It is also important to remember that statutory annual leave entitlement is separate from sickness absence rights. Where relevant to how the business manages leave generally, see holiday entitlement.

Section A summary: An employee is legally entitled to call in sick after a holiday request has been refused if they are genuinely unwell. Timing alone does not make the absence unauthorised or dishonest. At this stage, employers must focus on lawful absence management, not punishment. The decision to treat the absence as misconduct can only come later, and only if evidence supports it.

Section B: Does refusing the holiday strengthen the employer’s position if the employee then calls in sick?

Employers often assume that because they have lawfully refused an annual leave request, any subsequent sickness absence on that day is inherently suspect and easier to challenge. From an operational perspective, that instinct is understandable. From a legal and compliance perspective, it is incorrect.

Refusing a holiday request does not weaken an employee’s right to take sick leave, nor does it lower the legal threshold the employer must meet before treating the absence as misconduct. Holiday entitlement and sickness absence sit under different statutory frameworks. One does not cancel out or dilute the other.

1. The legal framework governing holiday refusal

Under the Working Time Regulations 1998, workers are entitled to 5.6 weeks’ paid annual leave per leave year. Employers are permitted to control when that leave is taken, including refusing specific dates, provided they give the correct statutory counter-notice. There is no general requirement in the Regulations for an employer to justify a refusal.

That said, any refusal must not breach the employee’s contract of employment and must not be discriminatory or retaliatory. In practice, most employers will provide reasons to maintain employee relations and to support workforce planning. For background on how holiday entitlement operates in practice, see statutory holiday entitlement.

Crucially, a lawful refusal of holiday does not carry any implied finding about an employee’s later fitness for work. UK employment law does not recognise a principle that an employee “should have booked holiday instead of being sick”.

2. Why refusal does not reduce sickness protection

Sickness absence is authorised by law where the employee is genuinely unwell and complies with reporting requirements. That position is unaffected by the employer’s earlier decision to refuse leave. Even where the refusal was clearly justified on business grounds, it does not give the employer greater latitude to question sickness or to treat the absence as unauthorised.

This point is frequently misunderstood by managers and is a common source of legal error. Treating a refused holiday as leverage in a sickness dispute often leads directly to procedural unfairness.

3. When the refusal becomes relevant later

Although refusing holiday does not reduce sickness protection, it can become relevant later as part of the wider factual context. Tribunals will look at the overall picture when assessing whether an employer acted reasonably. A refused holiday followed by sickness may contribute to that context, but it can never stand alone as evidence of dishonesty.

The refusal is most relevant when assessing:

• whether the employer’s decision-making was consistent and documented
• whether concerns were reasonable rather than arbitrary
• whether any later investigation was proportionate and fair

If the refusal was poorly handled, inconsistent or unexplained, the employer’s credibility later weakens. If it was handled transparently and consistently, it is easier to explain why concerns arose, even if those concerns cannot immediately justify action.

4. What employers should do at the point of refusal

Holiday refusals should not be treated as routine administrative decisions. Employers should ensure that refusals:

• comply with statutory notice requirements
• are applied consistently across comparable roles and teams
• are communicated clearly and calmly
• avoid language that implies suspicion or blame

Clear communication at this stage reduces resentment and lowers the risk that a later sickness absence becomes adversarial. It also supports the employer’s position if absence patterns later need to be reviewed.

5. Commercial consequences of poor handling

A poorly managed holiday refusal can have consequences far beyond a single day’s absence. It can trigger disengagement, increase absence-related disputes and undermine the employer’s credibility in later disciplinary proceedings. Where refusals appear arbitrary, tribunals are more likely to scrutinise how the employer responds to subsequent sickness.

Section B summary: Refusing a holiday request does not strengthen an employer’s legal position if the employee later calls in sick. The two rights operate independently. However, how the refusal is handled can materially affect credibility, risk exposure and the defensibility of later decisions. Employers should treat holiday refusals as potential compliance pressure points, not routine administration.

Section C: Is calling in sick after a refused holiday an unauthorised absence?

Employers frequently describe sickness following a refused holiday as an “unauthorised absence”. While the label may feel intuitive from an operational perspective, it is one of the most legally dangerous shortcuts an employer can take. Misclassification at this stage often undermines otherwise defensible decisions and exposes the business to wage claims and unfair dismissal risk.

The correct legal question is not whether the employer authorised the absence. It is whether the employee was genuinely unfit for work and whether they complied with the employer’s sickness reporting requirements.

1. What unauthorised absence actually means in law

An unauthorised absence is not simply an absence the employer does not approve of. In legal terms, it usually arises where an employee:

• fails to attend work without explanation
• fails to follow sickness notification procedures
• is absent without contractual or statutory justification

Genuine sickness absence does not require employer permission. It is authorised by law, not management discretion. This remains the case even where the absence coincides with a previously refused holiday request.

An absence only becomes unauthorised where there is evidence that the sickness is not genuine, or where the employee has breached reporting rules. Employers who conflate inconvenience with unauthorised absence place themselves on legally unsafe ground.

2. Why early reclassification creates legal risk

Employers sometimes reclassify sickness absence as unauthorised or dishonest immediately, particularly where the operational impact is significant. This approach creates multiple legal problems.

First, it risks unlawful deduction of wages if sick pay is withheld without lawful justification. Secondly, it undermines any later disciplinary process by demonstrating that the employer pre-judged the issue. Thirdly, it increases the likelihood of grievance or constructive dismissal claims based on breach of mutual trust and confidence.

Tribunals are consistently critical of employers who start from the position that an employee “must be lying” and work backwards to justify that conclusion.

3. Correct employer approach at this stage

At this point, employers should focus on process rather than outcome. A legally robust approach includes:

• recording the absence as sickness pending clarification
• checking whether reporting requirements were followed
• gathering factual information rather than assumptions
• maintaining neutral language in records and communications

Employers should also ensure that payroll, HR and line management records are aligned. Inconsistencies between absence records and disciplinary allegations are frequently exploited in tribunal proceedings.

For employers managing different working patterns, it is also important to ensure consistency across the workforce. Absence rights apply regardless of hours worked or contractual label. See employment law for part-time workers for further context.

4. Commercial implications of misclassification

While restraint at this stage may feel frustrating, it protects the employer’s longer-term position. Acting prematurely may satisfy immediate operational concerns but often creates greater cost later through grievances, legal advice and management time.

Maintaining procedural discipline preserves flexibility. It allows employers to escalate matters later if evidence emerges, without having already committed to a legally indefensible position.

Section C summary: Calling in sick after a refused holiday is not automatically an unauthorised absence. Genuine sickness is authorised by law, not employer permission. Employers who misclassify the absence too early risk wage claims, procedural unfairness and loss of credibility. The correct approach is to treat the absence as sickness initially, while preserving the ability to investigate if justified.

Section D: When does suspicion become a disciplinary issue for employers?

Suspicion alone is not enough to justify disciplinary action. For an employer to move from absence management into misconduct territory, there must be a lawful basis to do so. UK employment law requires employers to meet a defined fairness threshold before treating suspected dishonesty as a disciplinary matter.

The key question is not whether the employer believes the employee was lying, but whether that belief is based on reasonable grounds following a reasonable investigation.

1. The legal test employers must satisfy

When disciplinary action progresses to dismissal, tribunals apply the well-established principles derived from British Home Stores v Burchell. While the Burchell test formally applies to dismissal decisions, its principles are routinely used by tribunals to assess the fairness of earlier disciplinary sanctions.

Employers must be able to show that:

• they held a genuine belief that the employee was dishonest
• that belief was based on reasonable grounds
• those grounds followed a reasonable investigation

Failure on any one of these elements will usually render disciplinary action unfair, regardless of how suspicious the timing of the sickness absence appears.

2. What counts as reasonable grounds in practice

Reasonable grounds require more than coincidence or inconvenience. Factors that may contribute to reasonable grounds include:

• material inconsistencies in the employee’s explanations
• failure to comply with sickness reporting procedures
• evidence of activity incompatible with the claimed illness
• a demonstrable pattern of similar absences following refused leave

No single factor is automatically decisive. Even social media evidence must be approached with caution, as it may not accurately reflect an employee’s fitness for work at the relevant time.

3. Investigation before accusation

A common and serious employer error is to accuse first and investigate later. This reverses the legally required sequence and significantly weakens the employer’s position.

At this stage, employer action should be framed as fact-finding rather than fault-finding. This includes:

• asking neutral, open questions
• giving the employee a genuine opportunity to explain
• considering medical or contextual explanations
• avoiding language that implies guilt

Any investigatory meeting should be clearly distinguished from a disciplinary hearing. Blurring these stages is a frequent procedural error cited in unfair dismissal cases. Employers should ensure alignment with a fair disciplinary procedure and the ACAS Code.

4. Risks of escalating too early

Escalating too quickly into disciplinary action can expose employers to multiple risks, including:

• allegations that the outcome was predetermined
• claims of bias or bad faith
• breach of the ACAS Code of Practice
• increased compensation awards for procedural unfairness

Even where an employer later uncovers evidence supporting its suspicions, early missteps can fatally undermine the fairness of the process and increase unfair dismissal exposure.

Section D summary: Suspicion becomes a disciplinary issue only when it is supported by reasonable grounds following a reasonable investigation. Employers must separate instinct from evidence and investigation from accusation. Acting too early, or without procedural discipline, is one of the fastest ways to turn a manageable absence issue into a legally expensive dispute.

Section E: Can employers challenge sickness while the employee is off work?

When an employee calls in sick on a declined holiday, employers often want immediate clarity. Operational pressure, staffing gaps and prior suspicion all push towards early intervention. Legally, however, this is one of the most sensitive stages in the process. Employers must balance their right to manage attendance against the risk of being seen to challenge an employee’s health without evidence.

The law does not prohibit employers from asking questions during sickness absence. It does, however, restrict how those questions are framed and the conclusions that can be drawn.

1. What employers are entitled to ask

Employers are entitled to enforce their sickness reporting procedures. This includes requiring employees to notify absence within specified timeframes, provide a reason for absence and maintain reasonable contact during sickness absence.

Where an absence lasts more than seven calendar days, employers are entitled to require a fit note. Before that point, self-certification applies and employers must accept the employee’s explanation unless there is a clear breach of reporting rules. Further detail is set out in our guidance on self-certification rules.

Employers can ask questions to clarify fitness for work and anticipated return dates, particularly where there are operational implications. What they cannot do is demand medical proof earlier than permitted by law or imply dishonesty without reasonable grounds.

2. Pre-emptive conversations and legal boundaries

Some employers consider addressing rumours or concerns directly with the employee before or during the sickness absence. This is not unlawful in itself, but it carries risk. Any pre-emptive conversation must be genuinely exploratory rather than accusatory.

Employers should avoid:

• suggesting that the sickness is not believed
• threatening disciplinary action prematurely
• linking pay or job security to the explanation given

Instead, the focus should remain on understanding the situation, reminding the employee of applicable policies and ensuring reporting requirements are met. Conversations should be documented and handled consistently across the workforce to reduce allegations of unfair treatment.

3. Contact during sickness absence

Maintaining contact during sickness absence is lawful where it is reasonable and proportionate. Employers may check on an employee’s wellbeing, expected return date or handover arrangements. However, excessive contact or pressure to return can amount to harassment or a breach of trust and confidence.

The legal risk increases significantly where the employee’s illness may relate to stress, mental health or a long-term condition. In such cases, employers should consider whether additional duties arise under the Equality Act 2010 and whether medical input is appropriate.

From a pay perspective, employers should also remain mindful of ongoing sick pay obligations. Incorrect handling at this stage can create disputes about entitlement later, particularly where absence extends and questions arise about what happens when sick pay runs out.

Section E summary: Employers can ask questions and enforce reporting requirements while an employee is off sick, but must avoid accusations, demands for proof beyond legal limits or undue pressure. Early overreach risks undermining trust, breaching statutory protections and weakening any later disciplinary case. A controlled, neutral and policy-led approach is essential.

Section F: How should employers use return-to-work interviews after a suspicious absence?

Return-to-work interviews sit at the intersection of health and safety, absence management and misconduct risk. When an employee has called in sick on a declined holiday, the return-to-work interview is often the first lawful opportunity for an employer to explore concerns in a structured and defensible way.

Handled correctly, a return-to-work interview allows employers to gather information, test consistency and reinforce expectations without making accusations. Handled poorly, it can become evidence of pre-judgment or bias and significantly weaken any later disciplinary action.

1. The lawful purpose of a return-to-work interview

Return-to-work interviews serve several legitimate and legally recognised purposes. These include confirming that the employee is fit to return to work, identifying any ongoing health issues or adjustments that may be required, understanding the reason for absence and supporting future attendance.

They are not disciplinary hearings. However, that does not mean they are irrelevant where there are concerns about honesty. Employers are entitled to ask questions to clarify inconsistencies, provided the discussion remains neutral and exploratory rather than accusatory.

For employers managing repeated or extended absences, this process often sits alongside wider long-term sick leave and absence management arrangements.

2. What employers can and should ask

In cases involving suspected non-genuine sickness, employers should focus on factual clarification rather than challenge. Appropriate areas of questioning include:

• the nature and duration of the illness
• whether medical advice was sought
• whether the employee remains fully fit for work
• whether sickness reporting procedures were followed

If the explanation given differs from earlier accounts, this can be noted and, where appropriate, explored further through a separate investigation. The return-to-work interview itself should not be used to determine guilt.

3. What employers must avoid

Return-to-work interviews frequently go wrong where managers treat them as informal disciplinary ambushes. Employers should avoid:

• accusing the employee of lying or exaggeration
• relying on rumours or hearsay
• suggesting disciplinary sanctions during the meeting
• drawing conclusions without investigation

Any indication that the employer has already decided the sickness was not genuine can seriously undermine later disciplinary action and expose the business to procedural unfairness arguments.

4. Using the interview to decide next steps

The purpose of the return-to-work interview is not to reach a finding, but to decide what happens next. Possible outcomes include:

• no further action where the explanation is credible
• monitoring attendance patterns over time
• seeking medical input where appropriate
• initiating a separate investigation if reasonable grounds exist

Separating these stages helps demonstrate procedural fairness and preserves flexibility if concerns later escalate.

Section F summary: Return-to-work interviews are a lawful and valuable tool when an employee has called in sick on a declined holiday. They allow employers to gather information and assess credibility without breaching legal boundaries. The key is neutrality. Used properly, they protect the employer’s position. Used improperly, they can fatally undermine it.

Section G: Can employers withhold sick pay or SSP where they suspect dishonesty?

When an employee calls in sick on a declined holiday, employers often focus on whether they should still be paid. From a legal risk perspective, this is one of the most sensitive decisions an employer can make. Pay decisions taken too early, or based on suspicion rather than evidence, frequently result in unlawful deduction of wages claims and can fatally undermine any later disciplinary action.

The critical compliance point is that suspicion alone does not justify withholding sick pay.

1. Statutory Sick Pay: what the law requires

Statutory Sick Pay is a statutory entitlement, not a discretionary benefit. Where an employee meets the qualifying conditions, employers are required to pay SSP unless there is a lawful basis not to do so.

Calling in sick on a declined holiday does not, by itself, remove entitlement to SSP. Employers cannot lawfully withhold SSP simply because they believe the sickness is not genuine. SSP may only be withheld where:

• the employee does not meet statutory eligibility conditions
• the employee has failed to comply with statutory or contractual notification rules
• there is evidence that the employee was not actually sick

Importantly, SSP cannot be withheld as a disciplinary sanction. The employer must have evidence at the time the decision is made. Retrospective justification is unlikely to succeed if challenged.

Further detail on qualifying conditions can be found in our guidance on SSP eligibility, the current Statutory Sick Pay rate and the SSP claim process.

2. Contractual sick pay and limits of discretion

Many employers operate contractual sick pay schemes that go beyond SSP. While these schemes often allow a degree of discretion, that discretion is not unlimited.

Even where contractual sick pay is described as discretionary, employers must exercise discretion rationally, consistently and in good faith. Withholding contractual sick pay solely on the basis of suspicion, without investigation or evidence, risks breach of contract claims, constructive dismissal arguments and allegations of inconsistent treatment.

Employers should also ensure managers understand the distinction between statutory and contractual entitlements. Confusion at this level frequently leads to unlawful decisions. For an overview of how enhanced schemes are treated, see contractual sick pay schemes.

3. Payroll consistency and documentation risk

A common employer error is inconsistent internal handling. For example, recording an absence as sickness for HR purposes while withholding sick pay on the basis that it is “unauthorised”. Tribunals routinely scrutinise payroll records, HR systems and internal correspondence for consistency.

Where records conflict, tribunals often conclude that the employer did not genuinely believe the absence was misconduct at the time. This can seriously weaken both pay and disciplinary arguments.

4. Commercial consequences of getting pay decisions wrong

Incorrect pay decisions rarely resolve the issue. More often, they escalate it. Withholding pay frequently triggers grievances, formal disputes and legal advice, increasing cost and management time.

From a risk management perspective, it is usually safer to pay SSP, and contractual sick pay where appropriate, while preserving the employer’s ability to recover losses or impose sanctions later if dishonesty is established through a fair process.

Section G summary: Employers cannot lawfully withhold SSP or contractual sick pay merely because they suspect an employee has called in sick dishonestly after a holiday refusal. Pay decisions must be evidence-based, procedurally sound and compliant with statutory rules. Acting prematurely creates wage claims, undermines credibility and weakens any later disciplinary case.

Section H: When can dismissal be fair where an employee calls in sick on a declined holiday?

Dismissal for alleged dishonesty following sickness absence is one of the most heavily scrutinised decisions an employer can make. Where sickness coincides with a declined holiday, tribunals are alert to the risk that the employer acted out of frustration rather than evidence. As a result, employers must be able to demonstrate not only that dismissal was justified, but that it was a reasonable response in all the circumstances.

The fact that an employer strongly believes the employee was “pulling a sickie” is not enough.

1. The legal framework for fair dismissal

Under the Employment Rights Act 1996, a dismissal for misconduct may be fair if the employer can show a potentially fair reason, followed a fair procedure and reached a decision that fell within the range of reasonable responses open to a reasonable employer.

In cases involving suspected non-genuine sickness, the alleged misconduct is dishonesty. Tribunals accept that dishonesty can justify dismissal, but only where it is properly established through evidence and process.

Even where misconduct is proven, procedural defects can still render a dismissal unfair. Tribunals will apply the Polkey principle, meaning that procedural unfairness can invalidate a dismissal even if the outcome might otherwise have been justified.

2. Evidence thresholds employers must meet

To justify dismissal, employers will normally need clear and cogent evidence that the sickness absence was not genuine. This may include:

• credible evidence of activity incompatible with the claimed illness
• irreconcilable inconsistencies in the employee’s explanations
• a proven pattern of similar conduct following refused leave
• admissions by the employee

The higher the proposed sanction, the stronger the evidence must be. A single suspicious absence, without more, will rarely justify dismissal.

3. Proportionality and alternatives to dismissal

Even where misconduct is established, dismissal is not automatic. Employers must consider whether a lesser sanction would be reasonable, particularly where the employee has long service, a clean disciplinary record or where the operational impact was limited.

Failure to consider alternatives, such as a written warning, can render a dismissal unfair even where dishonesty is proven.

4. Length of service and residual risk

Employees with two or more years’ service can bring unfair dismissal claims. For employees with shorter service, unfair dismissal protection may not apply, but employers should not assume dismissal is risk-free.

Claims may still arise under discrimination law, whistleblowing protections or breach of contract. Opportunistic or poorly evidenced dismissals frequently trigger wider legal scrutiny.

For context on the scope of claims and potential exposure, see our guidance on unfair dismissal law and recent developments in unfair dismissal reform.

Section H summary: Dismissal for calling in sick on a declined holiday can only be fair where the employer has clear evidence of dishonesty, has followed a fair and procedurally sound process and has considered proportionality. Acting on suspicion alone is unlikely to be defensible and carries significant legal and commercial risk.

Section I: What hidden legal risks do employers often overlook in these cases?

One of the most common employer errors in cases involving sickness after a refused holiday is assuming the issue is confined to honesty or misconduct. In practice, these situations frequently engage wider statutory protections that significantly increase legal and commercial risk if overlooked. Employers who focus narrowly on suspicion can inadvertently expose the business to claims with uncapped compensation and serious reputational consequences.

The most significant hidden risks arise under the Equality Act 2010.

1. Disability-related sickness and the Equality Act 2010

Where an employee’s sickness relates to a physical or mental impairment that has a substantial and long-term adverse effect on their ability to carry out normal day-to-day activities, the employee may be protected as disabled under the Equality Act 2010.

In these circumstances, sickness absence is not simply an attendance issue. Employers have additional duties, including the duty to make reasonable adjustments and the duty not to treat the employee unfavourably because of something arising from their disability.

An employer who disciplines, withholds pay or dismisses an employee for sickness absence without considering whether disability is engaged risks a discrimination claim. Unlike unfair dismissal, compensation for discrimination is uncapped.

2. Mental health, stress and burnout-related absence

Mental health conditions, including stress-related illnesses, anxiety and depression, are increasingly recognised as disabilities for legal purposes. Sickness following a refused holiday may indicate workload pressure, burnout or unresolved workplace conflict rather than dishonesty.

Employers who treat stress-related absence as misconduct without investigation risk breaching their duty of care, failing to make reasonable adjustments and exposing the business to disability discrimination claims. These risks are amplified where managers focus on timing rather than underlying cause.

3. Pregnancy-related sickness and automatic unfairness

Pregnancy-related illness is afforded heightened legal protection. Any unfavourable treatment connected to pregnancy or maternity, including disciplinary action, pay decisions or dismissal, is likely to be unlawful regardless of length of service.

Employers must be particularly careful where sickness coincides with refused leave around antenatal appointments, fatigue or pregnancy-related complications. Even well-intentioned action can quickly become discriminatory if pregnancy is not considered.

4. Pattern-based assumptions and indirect discrimination

Employers sometimes rely on perceived patterns of absence, such as sickness around school holidays or peak trading periods. While patterns can be relevant, they can also mask indirect discrimination, particularly where certain groups are more likely to require time off for health, caring or religious reasons.

A rigid approach to absence management, even where applied consistently, can still be unlawful if it places certain groups at a particular disadvantage and cannot be objectively justified.

Section I summary: Cases involving sickness after a refused holiday often engage wider legal protections beyond misconduct. Disability, mental health and pregnancy considerations can transform a seemingly straightforward issue into a high-risk discrimination case with uncapped liability. Employers must widen their analysis, pause disciplinary instincts and assess whether additional statutory duties apply before taking action.

Section J: How should employers design policy and practice to reduce this risk?

Cases involving employees calling in sick on declined holidays are rarely isolated incidents. More often, they expose weaknesses in holiday management, absence monitoring or line manager capability. Employers who rely solely on disciplinary responses tend to see the issue recur, escalate or migrate into wider employee relations problems.

A preventative, policy-led approach is therefore not only safer from a legal perspective, but also more effective commercially.

1. Designing defensible holiday refusal processes

Holiday refusals should not be treated as informal or ad hoc decisions. From a compliance perspective, employers should ensure that holiday refusal processes are structured, consistent and properly documented.

In practice, this means ensuring that:

• refusal criteria are clear, objective and applied consistently
• statutory notice requirements under the Working Time Regulations are always met
• business reasons for refusal are recorded contemporaneously
• managers are trained to communicate refusals without escalation or implied blame

Transparency at this stage reduces resentment and lowers the likelihood that employees feel driven to sickness absence as an alternative to approved leave.

2. Strengthening absence management frameworks

A clear and accessible absence management policy is central to reducing misuse of sickness absence. Policies should set out:

• how and when sickness must be reported
• the operation of self-certification and fit note requirements
• how and when medical evidence may be requested
• how patterns of absence will be monitored and reviewed

Importantly, policies should emphasise that suspected abuse will be investigated fairly and proportionately, not assumed. For practical guidance on structuring compliant policies, see absence management policy guidance.

3. Training managers to handle grey areas

Line managers are often the weakest link in these scenarios. Poorly worded conversations, inconsistent treatment or informal accusations can undermine otherwise sound policies and expose the business to unnecessary risk.

Employers should ensure managers are trained to:

• separate suspicion from evidence
• use neutral, non-accusatory language
• escalate concerns appropriately rather than acting unilaterally
• document decisions accurately and contemporaneously

Manager capability is one of the strongest predictors of whether sickness-related disputes escalate into formal grievances or tribunal claims.

4. Aligning commercial realities with legal compliance

Employers must also recognise the commercial pressures that drive frustration in these scenarios, including deadlines, customer commitments and staffing shortages. Policies should allow for operational flexibility without encouraging legally unsafe shortcuts.

Measures such as incentivising cover during peak periods, planning holiday rotas well in advance and monitoring high-risk periods can reduce conflict without increasing legal exposure.

Section J summary: Employers cannot eliminate the risk of employees calling in sick on declined holidays, but they can significantly reduce it. Clear holiday refusal processes, robust absence management policies and well-trained managers provide the best defence. Prevention is cheaper, safer and more effective than enforcement after the event.

FAQs: Calling in sick on a declined holiday

1. Can an employee legally call in sick after a holiday request is refused?

Yes. An employee is legally entitled to call in sick if they are genuinely unwell, even where the sickness coincides with a previously refused holiday request. The timing of the absence does not, by itself, make the sickness unauthorised or dishonest.

2. Is calling in sick after a refused holiday automatically misconduct?

No. Misconduct only arises where there is evidence that the employee has been dishonest or has failed to comply with sickness reporting requirements. Suspicion, inconvenience or coincidence is not sufficient to justify disciplinary action.

3. Can an employer treat this as an unauthorised absence?

Only where the sickness is not genuine or the employee has breached absence notification procedures. Genuine sickness absence is authorised by law, not by employer permission, even where a holiday request has been refused.

4. Can employers ask for medical evidence straight away?

No. For the first seven calendar days of sickness absence, employees are entitled to self-certify. Employers may ask questions to clarify fitness for work, but they cannot demand a fit note or other medical evidence before the statutory threshold.

5. Can Statutory Sick Pay be withheld if the employer thinks the employee is lying?

No. Statutory Sick Pay cannot be withheld on the basis of suspicion alone. SSP may only be withheld where eligibility conditions are not met, reporting rules have been breached or there is evidence that the sickness was not genuine. SSP cannot be used as a disciplinary sanction.

6. Can contractual sick pay be withheld?

Possibly, but only if the employer’s sick pay policy allows for discretion and that discretion is exercised reasonably, consistently and in good faith. Withholding contractual sick pay purely on suspicion carries legal risk.

7. When can disciplinary action be started?

Disciplinary action may only be started where the employer has reasonable grounds, supported by a reasonable investigation, to believe that the sickness was not genuine. Employers must follow a fair process in line with the ACAS Code.

8. Is dismissal ever fair in these cases?

Dismissal may be fair where there is clear evidence of dishonesty, a fair and proportionate process has been followed and dismissal falls within the range of reasonable responses. A single suspicious absence will rarely justify dismissal on its own.

9. What if the sickness relates to stress, mental health or disability?

Additional legal protections may apply under the Equality Act 2010. Employers must consider whether reasonable adjustments are required and avoid unfavourable treatment arising from disability.

10. Can holiday leave be reclassified after sickness?

If an employee was genuinely sick, the absence should be recorded as sickness, not holiday. Holiday entitlement may be taken at another time in accordance with statutory rules and company policy.

Conclusion

Calling in sick on a declined holiday is one of the most legally sensitive absence scenarios employers encounter. While the timing often raises legitimate operational concern, UK employment law requires employers to distinguish suspicion from evidence and frustration from lawful process.

The law protects genuine sickness absence regardless of inconvenience or coincidence. Employers who rush to classify absence as unauthorised, withhold sick pay or initiate disciplinary action without proper investigation expose themselves to unnecessary risk. Unlawful deduction claims, unfair dismissal findings and discrimination liability frequently arise not because employers were wrong to be concerned, but because they acted too early or without sufficient evidence.

A defensible employer response requires discipline and restraint. This means treating sickness as sickness unless proven otherwise, preserving neutrality while gathering facts, using return-to-work interviews properly and making pay or disciplinary decisions only when legally justified. Where additional risks arise, such as disability, mental health or pregnancy-related illness, employers must pause and assess whether wider statutory duties apply.

Handled correctly, cases involving sickness after a refused holiday can be managed without escalation. Handled poorly, they are a common gateway to grievances, tribunal claims and reputational damage. The difference lies not in suspicion, but in evidence, process and compliance-focused decision-making.

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