Certificate of Sponsorship (CoS): Cost, Types and Timing

A certificate of sponsorship (CoS) is the electronic record a licensed UK employer gives you so you can apply for a work visa. It is not a paper certificate. It is an entry in the Home Office’s sponsorship system with a unique reference number, and you enter that number in your visa application. Without one, you cannot apply for a Skilled Worker visa.

Here is how a CoS works, what it costs, who pays, and the deadlines that catch people out.

What is a certificate of sponsorship?

GOV.UK describes it this way: an employer “must assign a certificate of sponsorship to each foreign worker” it employs, and “each certificate has its own number which a worker can use to apply for a visa.”

In practice, the employer fills in details about you and the job in the sponsorship management system (SMS), assigns the certificate, and sends you the reference number. Your visa application then pulls in or checks against that record. According to GOV.UK, the information you will need for a Skilled Worker application includes:

• your certificate of sponsorship reference number
• your job title and annual salary
• your job’s occupation code
• the name of your employer and its sponsor licence number, which will be on your certificate

If you don’t have a copy of the certificate, GOV.UK says to ask your employer for one. Check the details carefully. The salary and occupation code on the CoS decide whether you meet the Skilled Worker salary thresholds.

Who can issue a certificate of sponsorship?

Only an employer with a sponsor licence for the right route. The licence application fee is £611 for small or charitable sponsors and £1,682 for medium or large sponsors. GOV.UK says most applications are dealt with in less than 8 weeks.

The employer also needs a good licence rating. GOV.UK explains that a sponsor downgraded to a B-rating “will not be able to issue new certificates of sponsorship until” it has made improvements and returned to an A-rating.

Before you rely on a job offer, check that the company appears on the official register for the Skilled Worker route. Our guide to checking the register of licensed sponsors walks through it step by step.

Defined vs undefined certificates of sponsorship

There are two types, and which one you get depends on where you are applying from.

	Defined CoS	Undefined CoS
Used for	Skilled Worker applicants applying from outside the UK	Skilled Workers applying from inside the UK, plus all other visa routes
How the employer gets it	Applies for each one through the SMS	Allocated in advance; employers estimate their first-year needs when applying for the licence
Typical timing	Usually approved within one working day	Requests for extra certificates are usually decided within 12 weeks, or within 5 working days for a fee

So if you are moving from abroad, your employer requests a defined CoS for your specific role. If you are already in the UK, for example switching from a Graduate visa, you will usually be assigned an undefined CoS.

GOV.UK adds that delays are possible for both types if UKVI needs to carry out further checks.

Certificate of sponsorship fee: how much and who pays?

Certificate type	Cost per certificate
Worker (including Skilled Worker; not International Sportsperson)	£525
Temporary Worker	£55
International Sportsperson, CoS for more than 12 months	£525
International Sportsperson, CoS for 12 months or less	£55

For Skilled Worker, Global Business Mobility, Minister of Religion, International Sportsperson, Scale-up and Seasonal Worker sponsorship, GOV.UK says the employer must pay the certificate fee itself.

The immigration skills charge

When an employer assigns a CoS for a Skilled Worker or Senior or Specialist Worker visa, it may also have to pay the immigration skills charge:

Period on the certificate	Small or charitable sponsor	Medium or large sponsor
First 12 months	£480	£1,320
Each additional 6 months	£240	£660

The charge applies when the worker applies from outside the UK to work for 6 months or more, or from inside the UK for any length of time. GOV.UK lists exemptions for certain research and higher education occupation codes and for dependants. It also says the charge is not payable where the employer is “sponsoring someone to switch to a work visa from a visa that allows them to study”. Again, the employer must pay this itself.

Red flag: being asked to pay for your CoS

GOV.UK’s wording is clear: a sponsor’s “licence may be revoked if you ask the sponsored worker to pay the fee or any costs linked to your application.” If a recruiter or employer is selling “CoS jobs” or asking you to cover the certificate or skills charge, walk away. Some employers do choose to cover your visa fee and health surcharge, which is fine. Our Skilled Worker visa fees guide separates what you pay from what the employer pays.

How long is a certificate of sponsorship valid?

Two timing rules apply once your employer assigns your certificate:

1. You must apply for your visa within 3 months of the certificate being assigned.
2. You must not apply more than 3 months before the job start date listed on the certificate.

The Skilled Worker guidance also says you can apply up to 3 months before the day you are due to start work, and that date is the one on your CoS. If your start date moves, talk to your employer early so the record can be kept accurate.

Do you need a new CoS if you change jobs?

Often, yes. GOV.UK says you need to update your Skilled Worker visa if you change employer, or if you change to a job with a different occupation code (unless you are on a graduate training programme). A new employer will assign a new CoS. If you move to a job with a different occupation code at the same employer, GOV.UK’s sponsor guidance says the employer needs to assign a new certificate as well.

Don’t start the new job until your updated visa has been approved. You can apply up to 3 months before the new job begins.

Does a CoS guarantee a visa?

No. A CoS is required, but it is not a decision. The Home Office still assesses your application against all the requirements, including salary, English, documents and suitability. Treat the CoS as your ticket to apply, not your approval.

If you plan to stay in the UK long term, your sponsoring employer will matter again at settlement. Skilled Worker indefinite leave to remain requires a letter confirming they still need you.

Frequently asked questions

What is a certificate of sponsorship?

It is an electronic record, not a physical document, that a licensed UK employer assigns to a worker it wants to sponsor. Each certificate has its own reference number, which the worker uses to apply for their visa.

How much does a certificate of sponsorship cost?

GOV.UK lists £525 per certificate for Worker routes such as Skilled Worker, and £55 for Temporary Worker routes. For Skilled Workers the employer must pay this fee itself, and may also have to pay the immigration skills charge.

How long is a certificate of sponsorship valid for?

Once it is assigned, the worker must use it to apply for their visa within 3 months, and must not apply more than 3 months before the job start date shown on the certificate.

Can I buy a certificate of sponsorship?

No legitimate sponsor should sell you one. GOV.UK says the employer must pay the certificate fee and immigration skills charge itself, and its licence may be revoked if it asks the worker to pay these or any costs linked to its application.

What is the difference between a defined and undefined CoS?

Defined certificates are for Skilled Worker applicants applying from outside the UK and are requested case by case, usually approved within one working day. Undefined certificates are for Skilled Workers applying from inside the UK and for other visa routes.