Defined & Undefined Certificates of Sponsorship

defined cos undefined cos


The Certificate of Sponsorship plays an important role in the UK’s work visa sponsorship system.

Reform of the UK points-based immigration system saw the Skilled Worker route replace the Tier 2 (General) visa, and the two types of Certificate of Sponsorship were revised. Restricted and unrestricted CoS are no longer issued and have been replaced by Defined and Undefined CoS.

One of the requirements of sponsored work routes such as the Skilled Worker visa and Global Business Mobility visas is that the applicant has a valid Certificate of Sponsorship from a licensed employer. The Certificate of Sponsorship is a reference number, and not a physical document. It is used by the employer to effectively self-certify that the worker meets the requirements of the visa route, including skill level and salary.

The sponsor has to assign the correct type of CoS to each worker it wants to sponsor under the points-based system. UKVI operates an online Sponsor Management System, the ‘SMS’. The SMS is used by sponsors to apply for and manage their licence. This includes requesting and allocating Certificates of Sponsorship to sponsored visa workers.

The worker then uses the CoS to make their visa application to the Home Office. The worker must apply for their visa within 3 months of the CoS being assigned to them, and no earlier than 3 months from the start date of their job.


Which visas require a Certificate of Sponsorship?

Workers being employed under temporary sponsored work visa categories, such as the Skilled Worker visa and Scale Up visa, require a CoS to be allocated by their UK employer. The cost of assigning a CoS depend on the type of licence the employer has:


Type of sponsor licence

Cost per certificate

Worker (except workers on the International Sportsperson visa) £239
Temporary Worker £25
International Sportsperson – where the certificate of sponsorship is assigned for more than 12 months £239
International Sportsperson – where the certificate of sponsorship is assigned for 12 months or less £25


Undefined CoS

Undefined CoS are for individuals switching to the skilled worker category from within the UK, or applying under one of the other visa routes from within the UK or overseas.

When an organisation makes their sponsor licence application, they submit a request for undefined certificates. The application will need to include evidence to support the requested amount of CoS, although there is no cap on the number of undefined CoS that can be assigned, provided the workers are eligible under the visa route and the sponsor pays the fee to assign each CoS.


Defined CoS

For skilled worker visa applications made from outside the UK, (not ICT applications), sponsors will need to apply for a defined CoS. This is a specific application to the Home Office, and details of the specific job and salary will need to be provided.

If the individual is seeking to trade points because their salary does is below the relevant minimum salary level the going rate, the CoS will need to explain how those points are claimed, such as whether the role is a shortage occupation, or the worker has a PhD in a relevant subject area.

Importantly, the organisation must hold an A-rated sponsor licence in order to be able to assign a defined CoS.

Applications are typically processed within a working day, unless further information is requested in relation to the role, the recruitment process or the job candidate.

Sponsors make their requests using the SMS, requesting a renewal of annual allocation. In addition, the Home Office sponsor guidance, ‘Manual 8 of 12: Creating and assigning CoS’, details the steps to take to create, assign or delete individual or batch CoS.


Undefined CoS for UK Expansion Workers

Organisations that have been given a provisional licence rating under the UK Expansion Worker route will only be permitted to assign one CoS. This CoS must be assigned the organisation’s Authorising Officer to enable them to travel to the UK.

Once the AO’s visa has been granted, the sponsor licence can be upgraded to an A-rating, enabling the organisation to request a further four CoS through the SMS.


Annual CoS allocation renewals

In March 2023 UKVI advised sponsor licence holders that CoS annual allocations are in most cases to be renewed automatically based on the number of CoS the organisation assigned in the preceding 12-month period. You can check your organisation’s CoS allocation on your SMS.


Annual CoS allocation year

A sponsor’s annual CoS allocation year will be determined by a number of factors.

Annual CoS allocation typically run 12 months from the date the sponsor licence was granted and, in subsequent years, 12 months from the date an allocation renewal request is granted.

The Annual CoS allocation (CoS Year) runs from 6 April to the following 5 April if:

  • the sponsor held a valid Tier 2 (General) or Tier 2 (Intra-Company Transfer) licence on 30 November 2020; and
  • this was converted into a Skilled Worker or Intra-Company routes licence on 1 December 2020: and
  • their allocation renewal has been automated.


The Annual CoS allocation (CoS Year) runs from 12 months from the date the sponsor allocation renewal request was granted in 2021 and, in subsequent years, 12 months from the date the sponsor allocation renewal request is granted if:

  • the sponsor held a valid Tier 2 (General) or Tier 2 (Intra-Company Transfer) licence on 30 November 2020; and
  • this was converted into a Skilled Worker or Intra-Company routes licence on 1 December 2020; and
  • the sponsor allocation renewal has not been automated.


Need assistance?

DavidsonMorris’ specialist immigration lawyers are on hand to advise on all aspects of sponsor licence management, including allocations of Certificates of Sponsorships. If you have a query about a request for CoS, or changes to the sponsorship rules under the new immigration system, contact us.

Last updated: 14 January 2024


Founder and Managing Director Anne Morris is a fully qualified solicitor and trusted adviser to large corporates through to SMEs, providing strategic immigration and global mobility advice to support employers with UK operations to meet their workforce needs through corporate immigration.

She is a recognised by Legal 500and Chambers as a legal expert and delivers Board-level advice on business migration and compliance risk management as well as overseeing the firm’s development of new client propositions and delivery of cost and time efficient processing of applications.

Anne is an active public speaker, immigration commentator, and immigration policy contributor and regularly hosts training sessions for employers and HR professionals

About DavidsonMorris

As employer solutions lawyers, DavidsonMorris offers a complete and cost-effective capability to meet employers’ needs across UK immigration and employment law, HR and global mobility.

Led by Anne Morris, one of the UK’s preeminent immigration lawyers, and with rankings in The Legal 500 and Chambers & Partners, we’re a multi-disciplinary team helping organisations to meet their people objectives, while reducing legal risk and nurturing workforce relations.

Legal Disclaimer

The matters contained in this article are intended to be for general information purposes only. This article does not constitute legal advice, nor is it a complete or authoritative statement of the law, and should not be treated as such. Whilst every effort is made to ensure that the information is correct at the time of writing, no warranty, express or implied, is given as to its accuracy and no liability is accepted for any error or omission. Before acting on any of the information contained herein, expert legal advice should be sought.

Contact DavidsonMorris
Get in touch with DavidsonMorris for general enquiries, feedback and requests for information.
Sign up to our award winning newsletters!
Find us on: