Certificate of Sponsorship UK – What Employers Need to Know

If you’re sponsoring international talent into the UK, the Certificate of Sponsorship (CoS) is the document that makes it possible. This guide explains what a Certificate of Sponsorship is, the difference between a Defined CoS and an Undefined CoS, what it costs, and what your business needs to do before and after you assign one.

It’s written for International Expansion Managers, HR Directors, COOs, and founders at Nordic and international companies expanding into the UK, or already operating here with sponsored staff on the books. Across most UK visas that involve an employer, from a Skilled Worker visa through to the various Global Business Mobility categories, a Certificate of Sponsorship sits at the centre of the visa process, so getting comfortable with how it works pays off well beyond your first hire.

What Is a Certificate of Sponsorship?

A Certificate of Sponsorship (CoS) is a document issued by a licensed sponsor via their sponsor management system, that allows a migrant worker to apply for a UK visa under a sponsored route, most commonly the Skilled Worker visa. Every sponsored worker needs one before they can apply for their Visa. Without a valid CoS, there’s no visa application to submit.

The certificate confirms the job, the salary, the employer, and the visa category the worker is applying under. UKVI checks this information against the visa application itself, so accuracy matters from the first assignment.

Not every route among UK visas works the same way. Where migrants are sponsored by their employer, most commonly on the Skilled Worker or Senior or Specialist Worker route (formerly known as intra company transfer), both need a Certificate of Sponsorship. Additional routes such as the Expansion visa route and the International Sportsperson visa also require a Certificate of Sponsorship.

Visa types which are also commonly seen by UK employers are Student visa’s and Graduate visa’s. Neither use Certificate of Sponsorship, Student visas use a Confirmation of Acceptance for Studies rather than a CoS, issued by a licensed education sponsor instead of an employer. Global Talent visa’s are a visa type obtained directly by the employee if they are eligible for this category, they don’t require sponsorship at all. Knowing which visa category applies to your hire is the first step, before you even think about defined or undefined status. UK visas for overseas workers vary widely in their visa requirements, so treat each application on its own terms rather than assuming one certificate of sponsorship process covers every route.

Visa Category	Needs a Certificate of Sponsorship?
Skilled Worker visa	Yes, Defined or Undefined depending on location
Senior or Specialist Worker	Yes, always Defined
UK Expansion Worker	Yes, always Defined
International Sportsperson visa	Yes
Student visa	No, uses a Confirmation of Acceptance for Studies instead
Global Talent visa	No sponsorship required and obtained independently by the migrant

 

Foreign nationals switching between temporary worker categories, or switching positions need a fresh certificate rather than carrying an existing one across. Each temporary worker visa category has its own visa criteria and its own occupation and salary rules, so check the specific requirements for the category your hire falls under rather than assuming the Skilled Worker rules apply everywhere.

Is a Certificate of Sponsorship a Physical Document?

No. A Certificate of Sponsorship (CoS) is an electronic record, not a physical document you print or post. Each one gets a unique reference number, generated inside the Sponsorship Management System (SMS), that the worker enters on their visa application. There’s no paper certificate to lose or forward, just a reference number and the underlying record held on file by the Home Office.

Who Issues a Certificate of Sponsorship in the UK?

Only a licensed sponsor can issue a Certificate of Sponsorship (CoS). Your sponsoring organisation needs a valid sponsor licence first, and a nominated Level 1 User assigns the certificate through your SMS account.

The Two Types of Certificate of Sponsorship

There are two types of Certificate of Sponsorship (CoS): Defined and Undefined. Which one you need depends on where the sponsored worker is applying from, not on the visa category itself. Getting the defined or undefined CoS choice wrong is one of the most common reasons a visa application stalls.

A defined certificate and an undefined certificate carry the same legal weight once assigned, but the process behind each is different, and mixing them up creates delay rather than saving time.

Defined CoS	Undefined CoS
Used for
Skilled worker applicants outside the UK who need to ask for permission to enter and work in the UK	Sponsored workers already legally in the UK, who could be working for another UK employer, or applying to extend their visa with you
Requested via
Individual Home Office request	Drawn from annual allocation
Typical decision time
1 working day (up to 5 if referred)	Instant, from your allocation, however delays apply if you need to request an allocation increase
Assignment deadline
Must be assigned to the migrant you wish to sponsor within 3 months of ~~within 90 days of ~~approval. Once assigned to the migrant, this must be used within 3 months of being passed to the migrant for their application.	Allocations sit on your licence until they expire at the year end anniversary of your licence. Assigned CoS allocations must be used within 3 months once passed to a migrant you wish to sponsor. ~~No 90-day deadline; unused ones expire at year end~~

Defined CoS – For Skilled Workers Applying From Outside the UK

A Defined CoS is for skilled worker applicants applying from outside the UK. Your sponsoring organisation requests a Defined CoS through the SMS for each individual hire, providing job title, salary, occupation code, and personal details for the worker. UKVI typically decides Defined CoS requests within 1 working day, though this can take longer if the request is referred for further checks. Once approved, you must assign it within 90 days, or it’s removed from your account and you have to submit a new request.

Undefined CoS – For Workers Already in the UK

This certificate type, commonly called an Undefined CoS, covers sponsored workers already in the UK, such as someone switching visa category from a study route, switching employer or an existing employee extending their Skilled Worker permission. Unlike Defined CoS requests, an Undefined CoS is issued immediately from your existing allocation rather than requiring individual Home Office approval. If you’re unsure how many undefined certificates you’ll need in a given year, it’s worth overestimating slightly at the licence application stage, since running out mid-year means submitting a fresh allocation request. Be aware that Undefined CoS allocations are automatically renewed each year (unless you make a separate request through your licence) and will be based on the number of CoS you successfully assigned in the previous allocation year. Any unused CoS at the end of the allocation year will be lost, and won’t be carried through to the next allocation year.

Do You Need a Sponsor Licence Before Assigning a Certificate of Sponsorship?

Yes. You cannot assign a Certificate of Sponsorship (CoS) without holding a valid sponsor licence first. The sponsor licence is the authorisation; the CoS is the per-worker document you issue once you hold it. There’s no route to sponsoring a foreign worker that skips this step.

What Is a Valid Sponsor Licence?

A valid sponsor licence is Home Office authorisation, ~~granted for 4 years~~ confirming your business meets the requirements to sponsor overseas workers. It costs £611 for small or charitable sponsors and £1,682 for medium or large sponsors under current UK immigration law. Once granted, your business appears on the register of licensed sponsors and gains access to the sponsorship management system. Every certificate of sponsorship your business ever issues traces back to this one licence, so keeping it valid, and keeping your Authorising Officer and Key Contact details current, matters just as much as getting any individual CoS right.

A lapsed or revoked sponsor licence stops new certificates being issued immediately, and any Certificate of Sponsorship already in progress can be affected too. ~~This is one reason immigration lawyers recommend ~~ It is imperative to treat your sponsor licence compliance tasks seriously, regularly checking the validity of the information held on the Sponsor Management System, rather than treating this as routine admin; a business focused only on its next hire can lose sight of the licence underpinning every certificate it has already assigned to overseas workers.

How to Use the Sponsor Management System to Assign a CoS

Once you hold a sponsor licence, your Level 1 User logs into your SMS account to request or assign a CoS. For an Undefined CoS, this is a single step, drawn straight from your allocation should you have this available to you, taking into consideration that if you need to apply for an allocation increase then this will significantly increase the timeline involved. For a Defined CoS, you submit the request through the online sponsorship management system, providing role and salary details, and wait for the Home Office decision before assigning it to the named worker. The Authorising Officer retains overall responsibility for what’s assigned through the account, even where day-to-day tasks sit with a Level 1 User. A defined certificate and an undefined certificate both sit in the same sponsorship management system once issued, so a UK employer managing several sponsored roles at once can see the full picture in one place rather than tracking certificates across separate spreadsheets.

Your sponsorship licence and your SMS account are linked, so any change to your key personnel, business details, or trading status needs updating in the system promptly. UK employers sometimes treat the SMS as a one-off tool used only when hiring, but the Level 1 user should check it regularly, since the Home Office expects an online application form or update to be submitted within a set window whenever your circumstances change, not only when you’re assigning a new certificate.

Certificate of Sponsorship for the UK Expansion Worker Visa

The UK Expansion Worker route sits under the Global Business Mobility framework and works differently from a standard Skilled Worker CoS. It’s designed for overseas businesses setting up a new UK branch or subsidiary that hasn’t started trading yet, so the certificate of sponsorship rules reflect that early stage.

How the Defined CoS Works for UK Expansion Worker Applicants

Applicants under this route apply from outside the UK, so they always need a Defined CoS, never an Undefined one. Because the sponsoring business isn’t yet trading, UKVI grants a provisional rating rather than a full sponsor licence rating, and the licence itself is a Temporary Worker licence costing a flat £611, regardless of business size. The CoS fee for this route is £55, well below the £525 charged for Skilled Worker and Senior or Specialist Worker certificates, and there’s no Immigration Skills Charge to pay. A sponsor can assign a maximum of five certificates in total, and each worker can stay for up to two years with no settlement route attached. Once the UK business starts trading, the company need to apply to upgrade the licence rating to then apply for more regular routes, such as the Skilled Worker.

Certificate of Sponsorship Cost and the Immigration Skills Charge

Certificate of Sponsorship (CoS) cost isn’t a single fee. Budget for the CoS fee itself, the Immigration Skills Charge where it applies, and your visa applicant’s own visa application costs on top. Most UK employers underestimate the combined cost of a sponsored hire, since the sponsor licence application fee, the Certificate of Sponsorship fee, and the Immigration Skills Charge are three separate line items paid at different stages of the sponsorship process.

CoS Fee – What Employers Pay to Assign a Certificate

The CoS fee is £525 per certificate for the Skilled Worker route and the Senior or Specialist Worker route, and £55 for the pre-trading expansion route. This fee is non-refundable, even if you cancel the CoS or the visa application is later refused. Get the detail right before you assign it, since a mistake means paying the sponsorship fee twice. Every UK employer sponsoring a temporary worker under one of the lower-cost routes should still budget the full amount per visa applicant, since fee waivers are rare and generally tied to specific exemptions rather than business size.

Immigration Skills Charge – What It Is and How It Is Calculated

The Immigration Skills Charge applies to Skilled Worker and Senior or Specialist Worker certificates, paid upfront for the full length of sponsorship. Small or charitable sponsors pay £480 for the first 12 months and £240 for each further 6 months. Medium or large sponsors pay £1,320 for the first 12 months and £660 for each further 6 months. Most other Global Business Mobility routes, including the pre-trading expansion route, Graduate Trainee, Service Supplier, and Secondment Worker, are exempt from the Immigration Skills Charge, as are a small number of specific exemptions such as certain PhD-level roles.

CoS Allocation – How Many Certificates Can You Assign?

Your CoS allocation depends on the type of certificate. Undefined certificates come from an annual allocation set when you apply for your sponsor licence, and renewed each licence year; unused ones don’t carry forward. Defined certificates aren’t capped in the same way, since you request each one individually and UKVI decides case by case, though a pre-trading expansion sponsor is limited to five certificates in total. If your allocation of undefined certificates runs low, you can request additional CoS through the SMS, though processing can take several weeks unless a priority service is available. Reviewing your CoS allocation against actual hiring plans each quarter, rather than only at renewal, catches shortfalls before they become a problem for visa applicants waiting on an offer.

New CoS allocation requests go through the same SMS account as everything else. Larger sponsoring organisations with a steady pipeline of overseas workers tend to request a bigger undefined certificates allocation upfront, so a single hire doesn’t trigger an allocation review mid-year. Smaller UK employers, hiring one or two skilled workers a year, often find their initial estimate is enough and rarely need to request additional CoS beyond their first allocation.

A visa extension for a sponsored worker already on a Skilled Worker visa also draws on your undefined certificates, since the worker is applying from inside the UK. Visa extensions work the same way regardless of how long the worker has already been sponsored. The same applies to visa applicants switching categories, such as someone moving from a study-related visa onto a sponsored route, or a worker moving between specialist worker routes within the same sponsoring organisation. Neither scenario needs a Defined CoS, because neither applicant is outside the UK at the point of application. A single UK employer with several sponsored roles open at once should plan allocation around this pattern rather than requesting certificates one at a time.

How Long Does a Certificate of Sponsorship Take?

A Defined CoS request is typically decided within 1 working day, extending to around 5 working days if UKVI refers it for further checks. An Undefined CoS is available immediately, since it’s drawn straight from your existing allocation rather than requiring a fresh decision.

Once assigned, every Certificate of Sponsorship (CoS) is valid for 3 months. Your sponsored worker must submit their visa application within that window, and no more than 3 months before the job start date shown on the certificate. Visa processing times vary by route and by the applicant’s location, inside or outside the UK, so build a buffer into your recruitment timeline rather than assuming the fastest published visa processing times.

What Happens After a Certificate of Sponsorship Is Assigned?

Once assigned, the worker uses the CoS reference to complete their visa application. From that point, the electronic record sits against their name in the sponsorship management system, and your business is responsible for reporting any relevant changes to their employment status, salary, or role while their visa application, and later their employment, is live. Keep a note of the expiry date for the CoS itself, separate from the worker’s eventual visa expiry date, since missing the 3-month window means starting again with a new certificate and a new fee. This applies equally across UK visas, and to a defined certificate or one of your undefined certificates, since the underlying record for an overseas worker doesn’t change just because the certificate type does.

Reporting duties don’t end once the sponsored worker starts. If a foreign worker resigns, changes role, or stops attending work without explanation, your business must report this through the SMS within a set number of working days. Sponsoring organisations that fall behind on reporting duties for even one overseas worker risk a compliance visit, and repeated lapses can put the sponsor licence itself at risk, beyond the individual certificate.

The Resident Labour Market Test – When Does It Apply?

The resident labour market test no longer applies to the Skilled Worker route. It was abolished in 2020, and there’s no requirement to advertise a role domestically before sponsoring a foreign worker. In its place, UKVI applies a genuine vacancy requirement, checking that the role is real and the salary and SOC code genuinely match the job, rather than requiring formal proof of a UK-wide recruitment campaign.

Certificate of Sponsorship FAQs

Before the individual questions, here’s a quick reference for terms that come up throughout the sponsorship process:

Term	What It Means
CoS reference number	Unique code identifying a single certificate
Expiry date	3 months after assignment, when an unused CoS lapses
Job title	Must match the role advertised and the employment contract
Occupation code	The SOC code confirming skill level and going rate
Personal details	Full name, date of birth, and nationality of the visa applicant
Employment details	Salary, hours, and start date shown on the certificate
Sponsorship licence	The 4-year authorisation that makes assigning a CoS possible
New CoS	A fresh certificate, required after an expiry or a cancellation

 

If a query doesn’t fit neatly into the table, the answers below cover the questions UK employers ask most often about assigning and managing a Certificate of Sponsorship.

What Information Appears on a Certificate of Sponsorship?

A Certificate of Sponsorship (CoS) shows the sponsored worker’s personal details, their job title and occupation code, salary, employment details including start date and working hours, the sponsoring organisation’s name and licence number, and the CoS reference number itself. This applies equally to a defined certificate for a Skilled Worker visa applicant and an undefined certificate for someone already in the UK; the same fields appear on both. UKVI cross-checks all of this against the visa application, so it needs to match the employment contract exactly, right down to the job title used in both documents.

Can I Check a Certificate of Sponsorship Is Valid?

Yes. Your SMS account shows the current status of every certificate you’ve issued, including used, expired, or withdrawn status. A worker can also confirm their reference is genuine as part of their own visa application process, since UKVI validates it automatically against your sponsorship licence record. This check applies equally to a defined certificate and an undefined CoS, so there’s no separate process depending on certificate type.

What Happens If a Certificate of Sponsorship Expires?

If the 3-month window passes without a visa application being submitted, the certificate simply expires and can’t be revived or reused. Your business needs to assign a new CoS and pay the fee again, regardless of the original certificate type, defined or undefined. This is why timing the assignment around your visa applicant’s readiness matters more than assigning early out of caution. For a temporary worker certificate under a Global Business Mobility route, the same 3-month rule applies, so the visa requirements don’t relax just because the certificate cost less to begin with.

Can an Overseas Company with No UK Office Assign a Certificate of Sponsorship?

Generally, no. Most sponsor licence categories require a genuine UK trading presence before you can hold a licence and assign certificates to a certificate worker. The main exception is the UK Expansion Worker route, built specifically for overseas businesses that haven’t started UK trading yet (but must have a footprint), which lets you sponsor a small number of senior staff, under a provisional rating, to get the UK entity established, with a route to a full sponsor licence once trading begins. It’s a narrow exception under current UK immigration law, built for a specific stage of a business’s growth, not a general workaround for foreign nationals wanting to work for a company with no UK presence at all.

A few practical points come up often with overseas parent companies working through this for the first time. First, the sponsor licence application still needs a named Authorising Officer, Level 1 User and Key Contact. The initial Authorising Officer based overseas initially, would be the first migrant to be sponsored to come to the UK. Until the Authorising Officer moves to the UK (after the Expansion Visa is approved by UKVI) then no-one else can be sponsored under this route. For the purposes of the licence application, it is the business which sits overseas who is assessed to be a sponsor. Once the Authorising Officer is located in the UK, the Company can apply to increase their provisional rating to an A-grade rating, and once this is approved then up to 5 migrants from the parent company, who work in approved roles in line with establishing the UK entity and gearing it up for Trading, may be sponsored to come to the UK through this route. Once the Company start to trade, then it is possible to apply for other sponsorship routes, which offer more flexibility around job types which are eligible for sponsorship. Third, sponsoring organisations that skip proper legal advice at this stage often find their first sponsor licence application takes longer than expected, since UKVI scrutinises pre-trading applications more closely than an established sponsor licence renewal.

If your business already holds a sponsor licence overseas, that licence has no standing in the UK. A certificate of sponsorship issued by a non-UK entity carries no weight with UKVI, and every UK-facing certificate needs to come from a UK sponsor licence, granted under UK immigration rules, regardless of what sponsorship arrangements exist elsewhere in your group.

Setting Up in the UK – How Goodwille Supports the Process

Good with numbers, good with people, and good at getting international businesses trading in the UK without the guesswork. Sponsoring your first UK hire touches immigration law, HR compliance, and payroll all at once, and getting one piece wrong can hold up the others.

We support the full process: assessing your eligibility for a sponsor licence or the pre-trading expansion route, preparing and submitting your sponsor licence application, and managing your ongoing sponsorship management system administration once you’re licensed, from assigning your first Defined CoS through to ongoing compliance. That covers everything from a single skilled worker cos request to a sponsor management system set up for a growing team of skilled workers applying across several departments. Where a case needs specialist immigration lawyers, we bring that expertise in directly rather than leaving you to find it yourself, so you’re not piecing together immigration rules from separate advisers on top of everything else involved in setting up a UK entity.

If you’re planning to sponsor your first overseas hire, or you already hold a sponsor licence and want a second pair of eyes on your Certificate of Sponsorship (CoS) process, talk to our team. Good to go, from your first certificate onward.