What is a Certificate of Sponsorship?

Why is a CoS required?

The UK Government requires employers sponsoring overseas workers to demonstrate that:

• the employer is authorised to sponsor workers
• the job is genuine
• the worker has been offered an eligible role
• the salary meets the relevant immigration rules
• the employer accepts sponsorship responsibilities

A Certificate of Sponsorship helps the Home Office verify these details during your visa application.

Who can issue a Certificate of Sponsorship?

Only employers that hold a valid Skilled Worker sponsor licence can assign a Certificate of Sponsorship.

These employers are known as licensed sponsors.

Examples include:

• NHS Trusts
• Universities
• Engineering companies
• Care providers
• Technology companies
• Financial institutions
• Manufacturing businesses
• Hospitality employers

Before accepting a job offer, it is important to confirm that the employer is licensed to sponsor workers.

What information does a CoS contain?

A Certificate of Sponsorship includes information such as:

• your full name
• job title
• occupation (SOC) code
• salary
• weekly working hours
• work location
• sponsor licence number
• employer details
• start date
• end date (where applicable)
• sponsorship reference number

Your visa application is assessed using the information recorded on the Certificate of Sponsorship.

For this reason, all details should match your employment offer and supporting documents.

Is a Certificate of Sponsorship a Job Offer?

No.

A Certificate of Sponsorship is not the same as a job offer.

The normal order is:

1. Apply for a job.
2. Attend interviews.
3. Receive a job offer.
4. Accept the offer.
5. Employer issues your Certificate of Sponsorship.
6. Apply for your visa.

Receiving a CoS means your employer is supporting your visa application; it is not the document that creates the employment contract.

Types of Certificates of Sponsorship

There are different types of Certificates of Sponsorship depending on the immigration route.

For Skilled Worker applicants, the most relevant categories are:

• Defined Certificate of Sponsorship
• Undefined Certificate of Sponsorship

Defined vs Undefined CoS

Defined Certificate of Sponsorship

A Defined CoS is generally used when someone is applying for a Skilled Worker visa from outside the UK.

The sponsoring employer must request the Defined CoS from the Home Office before assigning it to the worker.

Undefined Certificate of Sponsorship

An Undefined CoS is generally used for workers who are already inside the UK and are eligible to apply from within the country.

Examples include people switching from another eligible visa route to a Skilled Worker visa.

How to get a Certificate of Sponsorship

Applicants cannot create or request one themselves.

Instead, the process typically works like this:

Step 1: Find a sponsoring employer

Apply for roles with employers licensed to sponsor Skilled Workers.

Step 2: Receive a job offer

If successful, the employer will issue a formal offer of employment.

Step 3: Employer prepares sponsorship

The employer checks that:

• the role is eligible
• salary requirements are met
• sponsorship conditions are satisfied

Step 4: Certificate assigned

The employer assigns your Certificate of Sponsorship electronically.

Step 5: Receive your reference number

You'll receive a unique CoS reference number, which you use in your visa application.

When should you receive your CoS?

Can you apply without one?

No.

In most Skilled Worker applications, a valid Certificate of Sponsorship is a mandatory requirement.

Without one, you cannot complete the application process.

How long is a CoS valid?

Once assigned, a Certificate of Sponsorship must generally be used within 3 months.

If you do not submit your visa application before it expires, your employer may need to assign a new Certificate of Sponsorship.

Always check the date on your CoS and apply as soon as possible.

Does a CoS guarantee visa approval?

No.

A Certificate of Sponsorship is an important requirement, but it does not guarantee that your visa will be approved.

The Home Office will also assess whether you meet all other applicable immigration requirements, such as identity, suitability, and the conditions of the Skilled Worker route.

Can One Certificate Be Used Multiple Times?

No.

Each Certificate of Sponsorship is unique.

It can normally be used for only one visa application.

Can Another Employer Use My Certificate of Sponsorship?

No.

Your Certificate of Sponsorship is linked to the employer who assigned it.

If you change employers and need sponsorship from a different licensed sponsor, a new Certificate of Sponsorship is generally required before applying to update your permission where the immigration rules require it.

Common mistakes applicants make

Applying before receiving a CoS

You should wait until your employer has assigned your Certificate of Sponsorship.

Using incorrect information

Ensure your:

• passport
• personal details
• job title
• salary
• dates

match the information on your Certificate of Sponsorship.

Waiting too long

A Certificate of Sponsorship has a limited period of validity for making your visa application.

Submitting your application promptly can help avoid unnecessary delays.

Assuming sponsorship guarantees approval

A successful visa application depends on meeting all relevant immigration requirements, not only having a CoS.

Tips Before Accepting a Sponsored Job

Before accepting an offer, consider checking:

• whether the employer holds a valid sponsor licence
• the salary offered
• working hours
• occupation code
• job location
• employment contract
• any relocation support
• visa cost arrangements, where discussed with the employer

Asking questions early can help prevent problems later in the application process.

Frequently Asked Questions

Is a Certificate of Sponsorship free?

Applicants are not charged by the Home Office for the Certificate of Sponsorship itself. Employers pay sponsorship-related fees to the Home Office, although other visa-related costs (such as the visa application fee or Immigration Health Surcharge, where applicable) are separate.

Can I get a Certificate of Sponsorship without a job?

No.

A Certificate of Sponsorship is assigned after an eligible sponsoring employer offers you a qualifying role.

Can recruitment agencies issue a Certificate of Sponsorship?

Only if the agency itself is the licensed sponsor and will employ you; many recruitment agencies simply recruit on behalf of employers and cannot assign a CoS themselves.

Can I change employers?

Yes, but if your new role requires sponsorship, the new employer generally needs to assign you a new Certificate of Sponsorship before you make the relevant immigration application.

Can I check whether my employer is licensed?

Yes. The UK Government publishes a register of licensed sponsors, which you can use to verify whether an employer is authorised to sponsor Skilled Workers.

Final Thoughts

A Certificate of Sponsorship is one of the most important parts of a Skilled Worker visa application. It links your job offer to a licensed sponsor and provides the Home Office with key information about your employment.

Understanding how the process works can help you avoid delays and prepare a stronger visa application.

If you're still looking for employers that sponsor overseas workers, explore the latest visa sponsorship opportunities and practical immigration guides on Noborda. Our goal is to help international professionals find verified sponsorship opportunities and better understand the UK's work visa process.

Related Guides

• Skilled Worker Visa Salary Requirements (2026)
• Graduate Visa to Skilled Worker Visa Guide
• Skilled Worker Visa Refusal Reasons
• How to Find UK Visa Sponsorship Jobs
• UK Companies That Sponsor Skilled Workers
• Skilled Worker Visa Document Checklist

Disclaimer

The information in this article is provided for general informational purposes only and does not constitute legal or immigration advice. While we aim to keep our content accurate and up to date, UK immigration rules and Home Office guidance can change. You should always verify the latest requirements through official UK Government guidance and, where appropriate, seek advice from a qualified immigration adviser or solicitor. Noborda is an independent information platform and is not affiliated with the UK Government or the Home Office.