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Certificates of Sponsorship (‘CoS’) are electronic records which must be assigned for each migrant worker you employ. Each CoS will have a unique reference number which enables an applicant worker to apply for a visa.

Requirements for a Certificate of Sponsorship

In order to obtain a Certificate of Sponsorship from the Home Office, a sponsoring employer will need to complete a CoS form. The CoS form will ask for information such as the migrant’s personal information, contact details, work address(es) in the UK, job description, hours, salary, and start and end date of employment. The Certificate of Sponsorship must include the same details as stated in the applicant worker’s passport.

There are two types of CoS: Defined Certificates and Undefined Certificates. It is the sponsoring employer’s responsibility to determine which type of CoS is needed for the migrant worker. 

Undefined Certificates of Sponsorship are available to individuals who are seeking to switch into the Skilled Worker category from within the UK or extend their stay in the UK as a Tier 2 (General) / Skilled Worker migrant. They are also for those applying on the Intra-Company, T5 or T2 routes. If you have an Undefined CoS available, it can be assigned immediately to a migrant applying from within the UK. If you do not have one available, you will need to make an allocation request to the Home Office, which can take up to 18 weeks to process with the possibility of speeding this up by using a priority change of circumstances request.

Defined Certificates of Sponsorship are for Skilled Workers who are currently abroad. You must apply for a Defined CoS for an individual worker through the sponsorship management system (SMS). Applications are usually approved within one working day, but may take longer if UKVI needs to carry out further checks or requests further information. Once a Defined CoS has been approved, you can then assign it to the migrant.

It is your responsibility, as the employer, to ensure that the applicant worker is informed when a CoS is assigned. A CoS can only be used once and will expire if it is not used by the applicant worker within 3 months of the employer assigning it to them.

A CoS does not guarantee that a visa will be granted. Once you have assigned the CoS, the applicant worker will still need to submit a successful visa application under the Skilled Worker, Intra Company, Minister of Religion, Sportsperson, or one of the Temporary Worker categories of the points-based system.

To find out how our immigration barristers can assist your business to obtain a sponsorship licence, call our business immigration team on 0203 617 9173 or complete our enquiry form below.

Certificate of Sponsorship Allocation

Undefined Certificates of Sponsorship 

There is no limit to the number of Undefined sponsorship certificates available.

When you submit a Sponsor Licence Application you will be asked to estimate the number of Undefined Certificates of Sponsorship that you will need in the first year. You will need to provide evidence that you need the number of certificates applied for, and give the requisite details and documents for the role(s) and migrant(s).

Each year you can renew your annual allocation or make an in-year allocation request if you require further Undefined Certificates of Sponsorship. You will need to consider whether you need a CoS for a person who needs to extend their permission stay in the UK, or if you have an employee in a different category (such as Student or Youth Mobility Scheme) who will be switching into Skilled Worker, or an EEA national who is not applying for pre-settled or settled status. You will not need to factor in the calculation any potential migrants who you wish to sponsor who will be applying overseas, as they will require a Defined Certificate of Sponsorship and a different process applies, as detailed below.

Defined Certificates of Sponsorship

For Defined Certificates of Sponsorship, there is no longer a limit on the number available, and you are no longer required to apply on the first working day after the 5th day of each month. You can apply for the CoS at any time for the individual migrant worker who requires it. 

When requesting a CoS allocation, whether this is a Defined or an Undefined CoS, you should include details of the roles you wish to fill. For an Undefined CoS allocation request, you should provide details of the migrant, if known, and detail how the migrant was identified for the role. 

Certificate of Sponsorship Costs

When you assign a Certificate of Sponsorship you will ordinarily need to pay a fee:

  • £199 for a Worker
  • £21 for a Temporary Worker

For citizens of the following countries, however, Certificates of Sponsorship are free: Austria, Belgium, Croatia, Republic of Cyprus, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Luxembourg, Malta, Netherlands, North Macedonia, Norway, Poland, Portugal, Slovakia, Spain, Sweden, and Turkey.

If you assign a Certificate of Sponsorship to a worker applying as a Skilled Worker or Intra Company Transfer Migrant, you may also need to pay the Immigration Skills Charge.

How Our Immigration Barristers Can Help

Our business immigration barristers regularly assist employers to apply for and assign Certificates of Sponsorship to their workers in compliance with the requirements of the Immigration Rules and Sponsor Guidance.

Whether you require assistance with applying for an Undefined or Defined Certificate of Sponsorship, or assigning a Certificate of Sponsorship via the SMS, our immigration barristers can assist.

We pride ourselves on being approachable and proactive in understanding and meeting our business clients’ needs. We are a highly driven team, dedicated to providing clear and reliable immigration advice directly to employers as part of a professional and friendly service.

We can also assist with

  • Creating, Assigning and Viewing Undefined Certificates of Sponsorship

    Initially, your Undefined CoS allocation will be added to your SMS account, and you will have 12 months from the date your licence was granted to assign the CoS. After that time, any unassigned CoS will expire.

    Our immigration barristers regularly assist employers to prepare and assign Undefined Certificates of Sponsorship to Skilled Worker, Intra-company transfer, T2 or T5 prospective employees via the Sponsor Management System (SMS).

  • Applying for and Assigning Defined Certificates of Sponsorship

    Our immigration barristers regularly assist employers to apply for and assign Defined Certificates of Sponsorship.


To arrange an initial consultation meeting with one of our immigration barristers, contact our business immigration team on 0203 617 9173 or complete our enquiry form.

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