UK Certificate of Sponsorship (CoS) Complete Guide 2026
This guide explains the Certificate of Sponsorship for Skilled Worker visa applicants and their sponsors. It covers the two types, who assigns them, how long they take, and what they cost.
What is a Certificate of Sponsorship (CoS)?
Certificate of Sponsorship: definition
A Certificate of Sponsorship (CoS) is an electronic record of a job offer from a licensed sponsor. The sponsor assigns it to the worker it wants to employ. It confirms the job, the salary and the sponsor’s details. It also gives the worker the reference number for the Skilled Worker visa application.
A Certificate of Sponsorship is an electronic record, not a paper certificate. A licensed sponsor creates it in the Home Office Sponsorship Management System (SMS). It has a unique reference number. You enter that number on your Skilled Worker visa application. The certificate records the job, its occupation code, the salary and the start date.
Only an organisation with a sponsor licence can assign one. Search the UK Tier 2 sponsor list to find a sponsor. Then find the occupation code and going rate for the job in our SOC codes list.
Defined CoS vs Undefined CoS: Key Differences Explained
There are two types of certificate. The type you need depends on where you are when you apply for the visa. Both types cost the sponsor the same. Both lead to the same Skilled Worker visa.
| Feature | Defined CoS | Undefined CoS |
|---|---|---|
| Target applicant | Skilled Worker who applies from outside the UK | Skilled Worker who applies from inside the UK (to switch route, change sponsor or extend), and every other sponsored route |
| Application process | The sponsor requests one for each worker in the SMS | Taken from the company's yearly certificate allowance |
| Decision timeframe | Usually 1 working day, longer if the Home Office asks for more information | Immediate, if the sponsor has certificates available |
| Home Office fee | £525 per certificate | £525 per certificate |
| Immigration Skills Charge | Applies: £480 a year for small or charitable sponsors, £1,320 a year for medium and large sponsors | Applies at the same rates. Some workers are exempt, such as a worker who switches from a Student visa |
Some sponsors plan to hire people who are already in the UK. They estimate how many undefined certificates they need for the next year. A sponsor that hires from overseas does not need an allocation for those workers. It asks for each defined certificate when it has a named candidate and a confirmed job.
What Information is Recorded on a Certificate of Sponsorship?
The electronic record has six groups of information. The visa caseworker checks each one.
- Sponsor details: the organisation name, its sponsor licence number and its rating. A sponsor must have an A rating to assign a certificate to a new worker.
- Worker details: full name, date of birth, nationality and passport number. They must match the passport exactly.
- Role: the four-digit SOC 2020 occupation code, the job title and a summary of the duties. Find the code for a job in our SOC codes list.
- Pay: gross annual salary. Only guaranteed basic pay counts towards the going rate. Bonuses and most allowances do not count.
- Work location and hours: the address where the worker will be based, and the weekly hours. It also shows the start and end dates of the job.
- CoS reference number: the unique number that the worker enters on the visa application form.
How Employers Assign a CoS to Skilled Worker Visa Applicants
- The sponsor confirms that the role is an eligible occupation. The pay must be at or above the going rate.
- For a worker outside the UK, the sponsor requests a defined CoS in the SMS.
- The sponsor assigns the CoS to the worker and pays the £525 CoS fee. It also pays the Immigration Skills Charge where it applies.
- The sponsor sends the reference number to the worker. The worker applies for the visa within 3 months.
Check that you reach the required 70 points with the visa points calculator.
How Much Does a CoS Cost and Who Pays?
The sponsor pays £525 to assign each Skilled Worker certificate. In most cases it also pays the Immigration Skills Charge at the same time. This charge covers the full period of sponsorship. A small or charitable sponsor pays £480 for the first 12 months. A medium or large sponsor pays £1,320. Each extra 6 months costs half of the first-year amount.
A sponsor must not recover these costs from the worker. If it does, it can lose its licence. The worker pays the visa application fee and the Immigration Health Surcharge. Calculate both sides in the visa cost calculator.
CoS Processing Times and Home Office Allocation Quotas
The Home Office usually decides a defined CoS request within one working day. It takes longer when the Home Office needs to make more checks on the job or the sponsor. Undefined certificates come from the sponsor’s yearly allocation. A sponsor that uses all of them can ask for more through the SMS. It can also pay for a priority service to get a faster decision on that request.
What Happens After Your CoS Is Assigned?
An assigned certificate is valid for 3 months. Apply for the visa in that period. Do not apply more than 3 months before the start date on the certificate. When you apply, the status of the certificate changes to used. You cannot use it again, even if the Home Office refuses the application.
A sponsor can withdraw a certificate, and the Home Office can cancel one. Each of these stops the visa application. Sometimes the job changes before you apply, for example the salary, the start date or the site. Ask the sponsor to record the change in a sponsor note. The record must agree with your application form.
Do you plan to stay long term? Time on a Skilled Worker visa counts towards settlement. See the Skilled Worker visa ILR guide. Employers that do not have a licence can read how to apply for a sponsor licence.
Can You Verify a CoS Number Online? (Important Warning on Scams)
No. There is no public tool that checks a CoS reference number. Only the sponsor and the Home Office can see the SMS. A person who sells a CoS, or a “CoS verification”, is a scammer. A genuine sponsor never charges you for the certificate.
You can verify the employer. Use the sponsor licence checker and the revoked sponsor licences list before you accept an offer.
This guide is general information, not legal advice. Confirm the current rules on GOV.UK before you act.