What is a Certificate of Sponsorship (CoS)?
A Certificate of Sponsorship is an electronic record a licensed employer assigns to you. There is no paper certificate. Its reference number goes on your visa application, which you have 3 months to make.
What it is
A certificate of sponsorship (CoS) is created in the Home Office’s sponsorship system by your employer. It holds details of the job: the SOC code, salary, start date and hours. You don’t receive a paper certificate. You get a reference number to put on your visa application.
Only an employer with a sponsor licence can assign one.
Defined and undefined
| Type | Who it is for | How the employer gets it |
|---|---|---|
| Defined | Skilled Workers applying from outside the UK | Requested for each worker, usually approved within one working day (GOV.UK) |
| Undefined | Skilled Workers applying from inside the UK (for example switching from a Graduate visa), and other visa routes | From a yearly allocation the sponsor requests |
Timing
- You have to apply for your visa within 3 months of the certificate being assigned. After that it can’t be used, and the employer would have to assign a new one.
- You can’t apply more than 3 months before the job’s start date on the certificate.
- GOV.UK says a decision usually takes 3 weeks from outside the UK and 8 weeks from inside.
What the employer pays
The employer pays £525 for each certificate for a worker, and usually the immigration skills charge (a government charge for each sponsored worker): £480 (small or charitable sponsors) or £1,320 (medium or large) for the first 12 months. GOV.UK says the sponsor must pay these itself and can lose its licence if it asks the worker to pay them.
Your own costs, the visa fee and the immigration health surcharge, are separate.
How many certificates employers use
The Home Office released, under Freedom of Information, how many certificates each sponsor was assigned from 2021 to 2024 (every Skilled Worker sponsor) and used in 2025 (sponsors with 5 or more). We show those numbers on each company page on SponsorJobs. They show whether an employer has sponsored people before, and roughly how many.
What it means for your job search
The certificate comes at the end: after the offer, once the employer has decided to sponsor you. Before that, what you can check is whether the employer holds a licence and whether the job meets the Skilled Worker rules.
Check an employer’s licence · Check the SOC code and salary · Browse jobs
Common questions
Is a Certificate of Sponsorship the same as a visa?
No. It is a reference number from your employer that you use to apply for the visa. The Home Office still decides the visa application.
How long is a Certificate of Sponsorship valid?
You must apply for your visa within 3 months of it being assigned, and not more than 3 months before the job’s start date.
Who pays for the Certificate of Sponsorship?
The employer. It pays £525 per certificate and usually the immigration skills charge, and it can lose its licence if it asks the worker to pay them.