Health and Care Visa: Certificate of Sponsorship (CoS)

12 Minutes

The health and care visa is the visa IMG doctors need to work and live in the UK. Applying for this visa requires a range of documents, including the certificate of sponsorship – arguably the most important document you’ll need for the journey. It’s a document provided by the NHS trust you receive a job offer from, who are responsible for applying for it and then passing it on to you for your visa application.

What is a Certificate of Sponsorship (CoS)?

The certificate of sponsorship is an electronic record issued by the NHS trust you will work with as a doctor, which the Home Office then approves. It’s necessary for your health and care visa, as it proves your terms of employment, including the salary, start date, and general responsibilities.

The main part of the certificate of sponsorship you’ll need is the reference number, as you will use this number during your visa application. That said, you will usually receive your CoS in the form of a two page document that looks something like this:

Obtaining the CoS mainly lies in the hands of your NHS trust – they must apply for the CoS and then provide information, such as your job role and salary. A sponsor license is necessary for the trust to complete this and fortunately most NHS Trusts are recognised as A-rated sponsors. 

Why Are Certificates of Sponsorships Important?

Certificates of Sponsorships are necessary for all UK visa applications because it shows the home office that the hospital you will work for have a defined vacancy that they are willing to sponsor you to work in. They are also confirming that you have the experience, background, and knowledge of the English language needed to perform well in their role. As an IMG, the CoS shows you have an NHS role as soon as you enter the UK. Therefore, your health and care visa will only get accepted if you have a CoS.

Defined vs Undefined Certificate of Sponsorship

Previously, the two types of CoS were named “restricted” and “unrestricted”, but that has since changed. Now, the two types of certificates of sponsorships are called “defined” and “undefined.”

As an IMG doctor wanting to work in the NHS, you will be applying for a defined CoS, which is designed for overseas applications. On the other hand, undefined CoS are for residents of the UK or those wanting to get a visa extension.

You might apply for a visa extension in the future, and in that case, you’ll likely apply for a undefined certificate of sponsorship. However, as your first health and care visa, you will only apply for the defined version.

Obtaining Your Certificate of Sponsorship

Here are the documents you will need to get your CoS:


You will need your passport at multiple stages of the visa journey, including for your CoS.


IMGs need GMC registration for their licence to practise medicine in the UK. Most hospitals will accept your invitation to ID Check as evidence if you haven’t completed that yet but have it booked.

Police Clearance Certificate

You will need a police clearance certificate from every country you have lived in for more than twelve months over the past ten years. The only exception is if you are applying for a role as a biological scientist, biochemist, or physical scientist.

Proof of Address

Proof of address is also important; you’ll usually need two documents for this dated within the last 3 months and showing your current address. Note that this should be the address you are making your application from and the address that your passport will be returned to once your application is successful. There is a select list of accepted documents so make sure you are presenting something official.

References from Employers

Lastly, for your certificate of sponsorship, you must have references from your previous employers covering at least three years and a minimum of two different referees. You should get in touch with your employers for this.

Many of these documents are necessary for your general visa application, so you should have them to hand. You will provide these documents to the NHS trust so they can go ahead with the CoS application. From there, it is in the NHS trust’s hands.

How Long Does a CoS Request Take?

It can take as little as 48 hours for the request to be confirmed after the NHS applies for the CoS. One the CoS is returned with the details of the role itself your HR department will then assign your personal details to it and issue the certificate out to you. Whilst it take 48 from application to the CoS being returned, the reality is that it often takes 2-3 weeks as the HR department needs to assess the application, pay the fees and assign your details to the certificate.

Received Your CoS! What Next?

Once you receive your certificate of sponsorship from your NHS employer, you can begin the process of applying for your health and care visa!

Before that, however, it’s important to check the information on your CoS to ensure it’s all correct. Here are the things to look out for:


Are all the details on the CoS correct? Go through each part, ensuring that they are, such as your name, date of birth, and qualifications.


Check if the section labelled ‘tick to certify maintenance for the migrant’ has a ‘Y’ or an ‘N’. If it contains a ‘Y’ for yes, that means the NHS trust are verifying that they would maintain and accommodate your very first month of medical employment in the UK should you fall on any hardship. It doesn’t however entitle you to free accommodation or relocation expenses so do be aware of that.

If they have put ‘N’ for no then don’t worry, it simply means you’ll need to evidence that you have enough money in your bank to maintain yourself and your family during your first month in the UK.

What to Do if There’s an Error

Unlike with many other documents (such as your BRP), there is no need to reissue a brand-new certificate of sponsorship if there is an error. Instead, the NHS trust can simply add notes to the ‘sponsor notes’ section to reflect the mistakes and changes.           

How Long is the CoS Valid For?

Once the NHS trust provides a certificate of sponsorship, time is of the essence – it does not last indefinitely. From the moment you receive your CoS, you have a total of 90 days to apply for your health and care visa.

What Happens if You Want to Take a Different NHS Position?

If you receive an offer from a different NHS trust and want to take up that position instead, you must first withdraw the CoS from your current sponsor. To do this, email or write to the sponsor and wait five days for them to cancel it. If they don’t cancel it within five days, you’ll have to send them a reminder.

Only once your previous certificate of sponsorship gets cancelled can you apply for another. Once it is cancelled, you start the process again with the NHS trust you will be working for, which you will then use in your visa application. Cancelling a CoS is a significant waste of time and money for an NHS Trust which is just one reason why you should only ever accept posts you intend to take up.

In Summary

Much of the process of obtaining your CoS is out of your hands – it is mainly up to the NHS trust to provide you with one. Once you have it, you can use the reference number to send your health and care visa application.

If you are looking to work in the NHS or have any questions about relocating to the UK then contact us and we’ll be happy to help and guide you throughout your journey.