Certificate of Sponsorship (CoS) – UK

Who Needs a Certificate of Sponsorship?

A CoS is required for any overseas national who has accepted a job offer from a UK employer that is licensed to sponsor workers.The sponsoring employer must be fully compliant with UK Visas and Immigration (UKVI) requirements and authorised to issue certificates through the Sponsor Management System (SMS).Only approved individuals within the organisation—those with the appropriate level of access to the SMS—can assign a CoS.Once issued, a CoS is valid for 90 days. The worker must submit their visa application within this period. However, applications should not be made more than three months before the intended start date of employment.

Types of Certificate of Sponsorship

The current system recognises two types of Certificates of Sponsorship: defined and undefined.This replaced the earlier system of restricted and unrestricted certificates following changes introduced in December 2020.

Defined Certificates of Sponsorship are typically used when recruiting workers from outside the UK under the Skilled Worker route. Employers must apply for these through the SMS, and each request is reviewed by UKVI before approval. Once approved, the certificate becomes available in the system.

Undefined Certificates of Sponsorship are used for workers already in the UK who are switching into a sponsored route, such as the Skilled Worker visa. When applying for a Sponsor Licence, employers must estimate how many undefined certificates they will need for the first year.

In most cases, CoS requests are processed within one working day, although delays may occur if further information is required.

Visa Routes That Require a CoS

A Certificate of Sponsorship is required across a wide range of work-related visa routes, including:

• Charity Worker
• Creative Worker
• Government Authorised Exchange
• Global Business Mobility routes (such as Senior or Specialist Worker, Graduate Trainee, Service Supplier, Secondment Worker, and UK Expansion Worker)
• Health and Care Worker
• International Sportsperson
• Minister of Religion or Religious Worker
• Scale-up Worker
• Skilled Worker
• Seasonal Worker
• Workers under international agreements

Eligibility Criteria

The requirements for a Certificate of Sponsorship differ for employers and employees.

Employer Requirements

To sponsor workers, an employer must first obtain and maintain a valid Sponsor Licence. This involves meeting strict compliance standards, including:

• Carrying out proper right to work checks
• Keeping accurate and up-to-date records for all sponsored workers
• Reporting relevant changes to UKVI within required timeframes
• Demonstrating that the business is genuine, operational, and financially stable

The organisation must also have a clean compliance history. Previous immigration breaches or licence revocations may affect eligibility.

Employee Requirements

A CoS is intended for individuals who do not already have the right to work in the UK through other means, such as settled status or family-based immigration routes. To qualify, the role offered must meet the required skill level (usually RQF Level 3 or above) and the applicable salary threshold for the relevant visa route. The worker must also meet all visa requirements, including English language ability, financial criteria where applicable, and suitability checks such as a clean immigration and criminal history.

Applying for a Certificate of Sponsorship

Before assigning a CoS, the employer must hold a valid Sponsor Licence issued by the Home Office. As part of the licence application process, businesses must provide supporting documents to confirm that they are a genuine and legally operating entity in the UK. A covering letter is also required to give context to the application.

Setting Up as a Sponsor

Once licensed, employers manage all sponsorship activities through the Sponsor Management System (SMS).Within the business, specific roles must be assigned to oversee sponsorship:

• An Authorising Officer (a senior and responsible person)
• A Key Contact for communication with UKVI
• A Level 1 User to manage the SMS on a day-to-day basis

These roles are essential to maintaining compliance and ensuring that sponsorship duties are carried out correctly.

Choosing the Right Type of CoS

Employers must decide whether they require defined or undefined certificates, depending on where the worker is based. They must also estimate how many certificates they will need, particularly when applying for a licence. This estimate should be supported with evidence, such as details of roles and recruitment plans.

Defined Certificates of Sponsorship

Defined CoS are subject to approval by UKVI. When requesting one, employers must provide full details of the role, including job description and salary.Each request is assessed to ensure it meets immigration requirements. Once approved, the certificate is issued through the SMS.

Undefined Certificates of Sponsorship

Undefined CoS are more flexible. There is no limit on the number available, and they do not require individual approval before being assigned.Employers can assign these directly through the SMS, generating a unique reference number that the worker will use in their visa application.

How to Apply

Applications for a Sponsor Licence—and by extension access to CoS—are made online.Once the application is submitted, a submission sheet is generated. This must be signed and sent along with all required supporting documents.

Documents can be uploaded electronically and must:

• Be in PDF, JPEG, or PNG format
• Be clearly legible
• Have concise and descriptive file names

If documents are not in English or Welsh, certified translations must be provided.

Documents Required

The exact documents required will be listed on the submission sheet generated after the application is completed.

Typically, employers will need to provide:

• Details of the role being offered
• Information about the worker’s qualifications and experience
• Salary and employment terms
• Working hours and job responsibilities
• Start and end dates of employment
• Evidence of payment for the CoS
• Employer contact details

The Authorising Officer must sign the declaration, and all documents must be submitted within five working days.Any formal declarations must be witnessed by a qualified independent professional, such as a solicitor or notary.

Assigning a Certificate of Sponsorship

When assigning a CoS, employers must ensure that the role and candidate meet all relevant criteria.For defined CoS, a request must be submitted and approved before assignment. For undefined CoS, assignment can be completed directly through the SMS.Each certificate generates a unique reference number, which the worker uses when applying for their visa.

Sponsor Management System (SMS)

The SMS is the central platform for managing all sponsorship activity.

It is used to:

• Assign Certificates of Sponsorship
• Record changes in employment or worker status
• Report absences or compliance issues
• Maintain accurate and up-to-date records

Only authorised personnel should access and update the system, and it must be kept accurate at all times.

Making Changes to a CoS

Once a CoS has been assigned, only minor errors can be corrected. These include small issues such as spelling mistakes or incorrect dates of birth, which can be updated using a sponsor note in the SMS. If the error is significant—for example, a change in job role, occupation code, or visa route — the certificate must be cancelled and a new one issued. If a worker changes roles within the organisation, a new CoS must be assigned, and a fresh visa application may be required. The worker can usually continue in their current role while awaiting a decision.

Cancelling a Certificate of Sponsorship

A CoS must be cancelled within five working days if:

• The worker leaves the organisation
• Their role changes significantly
• They move to another employer

A worker can only hold one active CoS at a time. The existing certificate must be cancelled before a new one is issued. Failing to act within the required timeframe can lead to compliance issues and potential action from UKVI.