Illegal Immigrants: UK Rights, Removal & Work Rules 2026

Illegal immigrants is a phrase often used to describe people who are in the UK without valid immigration permission, but the term has no defined status in UK legislation.

An individual’s immigration position depends on whether they hold valid leave to enter or remain and whether they are complying with the conditions attached to that leave. Overstaying, unlawful entry and breach of visa conditions are treated differently under the Immigration Acts and carry distinct consequences.

This guide explains how unlawful status arises, what limited rights may still apply in certain circumstances and how the Home Office exercises its enforcement powers.

Section A: What Does “Illegal Immigrants” Mean Under UK Law?

The phrase “illegal immigrants” is widely used in media and political debate, but it is not a defined legal category under UK immigration legislation. The Immigration Acts and the Immigration Rules refer instead to individuals who are subject to immigration control and who either do not have valid leave to enter or remain, or who are in breach of the conditions attached to that leave.

In legal terms, status turns on whether a person has been granted permission to enter or stay in the United Kingdom and whether they continue to meet the terms of that permission. Someone who has never had leave, whose leave has expired, or whose leave has been curtailed may be present unlawfully. The law focuses on permission and compliance, not labels.

That distinction matters for employers and advisers. Using imprecise terminology risks misunderstanding the legal threshold that triggers civil penalties or criminal exposure. The issue is not whether someone is described as an “illegal immigrant”, but whether they have valid immigration permission and a right to work at the relevant time.

1. Is “Illegal Immigrant” a Legal Term in UK Immigration Law?

UK immigration legislation does not create a statutory category called “illegal immigrant”. Instead, it regulates entry and stay through the grant of leave. A person is either lawfully present under a grant of leave, or they are not. The terminology used in legislation refers to unlawful entry, overstaying, breach of conditions and liability to removal.

For compliance purposes, precision matters. Employers are not required to determine whether someone is an “illegal immigrant” in a political sense. They are required to establish whether that individual has permission to undertake the specific work offered. The statutory regime turns on that narrow but decisive question.

2. When Is a Person Considered to Be in the UK Unlawfully?

A person may be in the UK unlawfully where their leave has expired and no valid in-time application was made to extend or vary that leave. From the point of expiry, the individual no longer has permission to remain unless section 3C leave operates to extend their status while an application is pending.

Unlawful presence can also arise where entry occurred without permission, for example by evading border controls. In other cases, entry was lawful at the outset but subsequent conduct places the person in breach of their visa conditions. Working in excess of permitted hours, taking employment prohibited by visa conditions, or failing to comply with reporting requirements may all lead to curtailment and eventual loss of lawful status.

The position is therefore fact-sensitive. Administrative error, misunderstanding of visa conditions or failure to act promptly following curtailment can all result in loss of lawful status. For employers, the practical issue remains whether valid permission to work exists at the time employment begins and continues.

3. Do People Without Lawful Status Have Any Legal Rights?

Absence of lawful immigration status does not remove all legal protections. Certain fundamental rights continue to apply. Individuals may bring asylum claims or human rights claims, and removal action may be paused while those claims are determined. Emergency healthcare is available regardless of status, although charges may arise for non-urgent treatment.

In the employment context, courts have recognised that individuals without status may in limited circumstances pursue claims relating to exploitation, unpaid wages or discrimination. Modern slavery and trafficking protections apply irrespective of immigration status.

None of these protections alter the underlying immigration position. A person without valid leave remains liable to removal and may face re-entry bans depending on the circumstances. For employers, residual rights do not reduce the obligation to prevent illegal working. The statutory focus remains on permission to work, not on broader human rights protections.

Section B: Illegal Working and Employer Liability

Illegal working is defined by reference to permission. A person works illegally where they are subject to immigration control and either have no leave to enter or remain in the UK, or their leave does not permit the type of work in question.

The statutory framework sits primarily within the Immigration, Asylum and Nationality Act 2006. The Act imposes a positive obligation on employers to prevent illegal working. Liability does not depend on intention. An employer can incur a civil penalty even where there was no knowledge that the individual lacked permission, if prescribed right to work checks were not carried out correctly.

Illegal working therefore covers several scenarios. An individual may have no status at all. They may have overstayed. They may hold a visa that prohibits work entirely. Alternatively, they may have permission to work in limited circumstances but are undertaking work outside those limits, for example exceeding permitted hours under a Student visa or working in a role not covered by sponsorship.

From a compliance perspective, the legal test is binary. At the point employment begins and throughout its duration, the individual either has the right to perform that work or they do not. The employer’s exposure turns on whether the correct preventative steps were taken.

1. What Is Illegal Working Under the Immigration, Asylum and Nationality Act 2006?

Illegal working arises where an employer employs a person who is disqualified from employment by reason of their immigration status. The 2006 Act links liability to the absence of valid permission to work, not to broader questions about how the individual entered the UK.

The concept captures those with no leave, those whose leave has expired and those who are breaching specific work conditions. Employers are not expected to conduct immigration investigations, but they are required to verify the existence and scope of permission to work before employment begins and, where relevant, at follow-up intervals.

2. What Are the Civil Penalties for Employing Illegal Immigrants?

Where an employer is found to have employed a person without the right to work, the Home Office may issue a civil penalty. The maximum penalty applies per illegal worker and is determined by reference to a published code of practice. Aggravating and mitigating factors are taken into account, including previous breaches and cooperation with investigators.

The civil regime is administrative rather than criminal. A referral notice is issued, followed by a civil penalty notice if liability is established. Employers can object and, if necessary, appeal to the County Court. In practice, the decisive issue is whether a compliant right to work check was conducted and recorded in line with Home Office guidance.

Publication of penalties can have reputational impact. For sponsor licence holders, a civil penalty may also trigger wider compliance scrutiny.

3. When Does Employing an Illegal Worker Become a Criminal Offence?

The 2006 Act also creates a criminal offence where an employer knowingly employs a person who does not have the right to work, or has reasonable cause to believe that this is the case. The distinction between civil and criminal liability lies in knowledge and state of mind.

Reasonable cause to believe captures situations where warning signs were present and ignored. Obvious expiry of leave, inconsistent documentation or information suggesting breach of visa conditions may support an allegation that the employer ought to have known.

Conviction can result in an unlimited fine and, in serious cases, custodial sentences for responsible individuals. While most enforcement proceeds under the civil regime, criminal liability remains a real risk where there is deliberate facilitation or repeated disregard of compliance obligations.

For employers, the analysis requires clear internal processes, documented checks and escalation where doubts arise. The statutory excuse and right to work framework are examined in the next section.

Section C: Right to Work Checks and the Statutory Excuse

The civil penalty regime is built around prevention. Employers are given a defence, known as the statutory excuse, where they carry out prescribed right to work checks in accordance with Home Office guidance. The defence is procedural. It depends on evidence of compliant checks rather than on good faith or absence of intention.

Right to work compliance is therefore not an administrative formality. It is the legal mechanism that determines whether a civil penalty can be imposed. Where checks are incomplete, inconsistent or poorly documented, the excuse fails even if the employer believed the individual had permission to work.

1. How Do Employers Establish a Statutory Excuse?

An employer establishes a statutory excuse by conducting a prescribed right to work check before employment begins. The check may be carried out using the Home Office online service where the individual holds digital status, or by reviewing acceptable original documents where a manual check is permitted. The employer is required to confirm that the documents appear genuine and relate to the individual presenting them.

Where the individual has time-limited permission, follow-up checks are required before that permission expires. A failure to diarise and complete a repeat check can expose the employer to liability from the date the leave lapses.

The statutory excuse protects against civil penalties only. It does not provide immunity from criminal liability where there is knowledge or reasonable cause to believe that permission to work does not exist.

2. What Are the Most Common Compliance Failures?

Home Office enforcement action frequently arises from process failures rather than deliberate misconduct. Common issues include reliance on expired documents, failure to carry out follow-up checks for time-limited visas and inconsistent application of checking procedures across different departments or sites.

Employers also encounter difficulty where visa conditions are misunderstood. For example, a Student visa holder may have permission to work limited hours during term time but full-time during vacations. Without clear internal controls, hours can exceed permitted limits without immediate detection.

Poor record-keeping is another recurring issue. The statutory excuse depends on retaining evidence of the check. If documentation cannot be produced during an audit, the Home Office is likely to conclude that a compliant check was not conducted.

3. How Do Right to Work Checks Interact with Discrimination Law?

Employers are required to prevent illegal working while also complying with the Equality Act 2010. Applying right to work checks selectively based on nationality, ethnicity or perceived immigration status can give rise to discrimination claims.

The Home Office guidance is clear that checks should be carried out on all prospective employees before employment begins, regardless of their background. A uniform process reduces both civil penalty exposure and discrimination risk.

Tension can arise where employers seek additional reassurance from individuals who appear to have foreign nationality or accents. Over-checking certain groups or requesting unnecessary documentation can undermine compliance efforts and expose the organisation to parallel legal claims. A clear written policy, applied consistently, provides the strongest protection on both fronts.

Section D: Sponsor Licence Risk and Illegal Working

For sponsor licence holders, illegal working has consequences beyond the civil penalty regime. Sponsorship carries additional reporting and monitoring duties. A finding of illegal working may be treated as evidence that the sponsor has failed to discharge its wider compliance obligations.

The Home Office expects sponsors to maintain oversight of immigration status throughout employment. Where that oversight fails, enforcement action can extend to licence suspension, downgrading or revocation.

1. How Does Illegal Working Affect a Sponsor Licence?

A civil penalty for illegal working can trigger immediate scrutiny of a sponsor licence. The Home Office may conduct a compliance visit to assess whether systems are robust and whether sponsored workers are being managed in accordance with sponsor guidance.

Where serious breaches are identified, the licence may be suspended pending investigation. Revocation is possible where the Home Office concludes that the sponsor can no longer be trusted to meet its duties. Revocation results in curtailment of sponsored workers’ leave and can have significant operational impact.

Downgrading to a B-rating may also occur, requiring the sponsor to implement an action plan at additional cost and under heightened monitoring.

2. What Happens If a Sponsored Worker Becomes an Overstayer?

If a sponsored worker’s leave expires or is curtailed, and no valid application is made, the individual becomes an overstayer. The sponsor is required to report certain changes in circumstances through the Sponsor Management System, including termination of employment.

Continued employment of a sponsored worker without valid permission exposes the organisation to both civil penalty risk and sponsor compliance action. The fact that sponsorship previously existed does not shield the employer once leave has lapsed.

Clear internal communication between HR, compliance teams and line managers is necessary to ensure that visa expiry dates are monitored and acted upon promptly.

3. How Does the Home Office Investigate Illegal Working?

The Home Office conducts both announced and unannounced visits. Officers may request personnel files, right to work documentation and payroll records. They may interview staff and sponsored workers to test whether reported roles align with actual duties.

Investigations may also arise from data sharing across government departments or from third-party reports. Where illegal working is suspected, a referral notice is issued setting out the alleged breach and inviting representations.

The investigation process moves quickly. Deadlines for objection are strict, and failure to respond in time can limit options. Early legal advice is often decisive where significant financial or licence exposure is at stake.

Section E: Risk Management, Enforcement Response and Practical Steps for Employers

Illegal working exposure rarely arises in isolation. In most cases, it reflects gaps in internal systems, unclear accountability or inconsistent application of right to work procedures. Once a breach is identified, the focus shifts from prevention to damage control. Employers need to understand both their immediate obligations and the longer-term implications for compliance, reputation and sponsorship status.

The Home Office approach to enforcement is procedural and evidence-based. Organisations that can demonstrate clear systems, documented checks and active oversight are in a stronger position than those relying on informal practice or assumptions about status.

1. What Immediate Steps Should Employers Take If Illegal Working Is Discovered?

Where an employer discovers that an individual does not have the right to work, the first step is to verify the position carefully. Errors in documentation or misunderstandings about pending applications can arise. Confirmation should be obtained using the Home Office online checking service where appropriate.

If the individual does not have valid permission to work, continued employment will expose the organisation to civil and potentially criminal liability. Suspension may be appropriate while clarification is sought, but once lack of permission is confirmed, employment cannot lawfully continue.

Internal investigation should follow. Employers should review how the individual was recruited, what checks were carried out and whether systemic weaknesses exist. That review will be central if the Home Office later assesses whether mitigation applies in calculating a civil penalty.

2. How Can Employers Reduce Exposure to Illegal Working Penalties?

Risk reduction depends on consistent process rather than reactive intervention. A written right to work policy, applied uniformly across all hires, provides a defensible framework. Responsibility for conducting and recording checks should be clearly allocated, with oversight at senior level.

Visa expiry dates should be recorded and monitored through reliable tracking systems. Follow-up checks for time-limited permission are not optional. Failure to conduct a repeat check removes the statutory excuse from the date leave expires.

Training is equally important. Line managers and recruitment teams should understand that assumptions about nationality, accent or length of residence are irrelevant. The question is whether permission to work exists and has been verified in accordance with prescribed guidance.

Periodic internal audits can identify gaps before the Home Office does. Audit findings should be documented and remedial action taken promptly. Evidence of proactive compliance can be relevant where mitigation is considered.

3. Can Individuals Without Status Regularise Their Position?

Some individuals without lawful status may be able to submit further applications to regularise their stay, depending on their circumstances. Late applications, asylum claims or human rights applications can, in certain cases, provide temporary protection from removal while a decision is pending.

From an employer perspective, the existence of a potential future application does not in itself create permission to work. Only where a valid application has been submitted in time and section 3C leave applies will the individual retain lawful status and, in some cases, ongoing permission to work.

Employers should avoid offering immigration advice beyond signposting individuals to seek independent legal guidance. The organisation’s responsibility remains focused on verifying whether permission to work currently exists. Future possibilities do not substitute for present compliance.

Section F: Summary

The term “illegal immigrants” has no formal status in UK law. Liability turns instead on whether a person has valid permission to be in the UK and to carry out the work offered. For employers, the risk is procedural rather than political. Civil penalties, criminal exposure and sponsor licence action arise where right to work checks are not conducted correctly or where warning signs are ignored.

The statutory excuse remains the central safeguard. Clear policies, consistent checks and accurate record-keeping determine whether an organisation is protected. Immigration compliance is evidence-driven. Where documentation is weak, liability follows. Where systems are robust, exposure can be contained.

Section G: FAQs

What is the legal definition of an illegal immigrant in the UK?

UK legislation does not define “illegal immigrant” as a formal category. The law focuses on whether a person has valid leave to enter or remain and whether they are complying with the conditions attached to that leave.

What is the fine for employing an illegal worker in the UK?

Employers can face a civil penalty per illegal worker where a compliant right to work check was not carried out. The amount is determined under a Home Office code of practice and may increase for repeat breaches.

Can an employer go to prison for employing someone illegally?

Criminal liability may arise where an employer knowingly employs a person without permission to work or has reasonable cause to believe that this is the case. Conviction can result in an unlimited fine and, in serious cases, imprisonment.

Does carrying out a right to work check protect an employer?

A compliant right to work check carried out before employment begins can establish a statutory excuse against civil penalties. The defence depends on following prescribed guidance and retaining evidence of the check.

What happens if a sponsored worker becomes an overstayer?

If a sponsored worker’s leave expires and no valid application is made, the individual becomes an overstayer. Continued employment will expose the employer to civil penalty risk and potential sponsor licence action.

Section H: Glossary

Section I: Useful Links