Certificate of Sponsorship (CoS) Employer Guide, Cost & Timelines
A missed detail on a single electronic form can cost a business its next hire. That is the reality behind the certificate of sponsorship UK process; it looks like paperwork, but it decides whether your chosen candidate ever boards a flight to join your team. Every employer sponsoring a worker from overseas, or switching a candidate onto a Skilled Worker visa from inside the UK, must get this step right.
Yet many HR teams only discover the finer rules once a delay has already happened. This guide walks through what a CoS actually is, how much it costs, how long it takes, and which documents your team needs ready before you assign one, so nothing catches you off guard mid-hire. Think of it as the practical companion you wish someone had handed you before your first sponsorship case.
Quick Overview: What This Guide Covers
Before diving in, here’s the short version. A certificate of sponsorship UK visa applicants need is an electronic record, not a physical certificate, issued through the Sponsorship Management System (SMS). It comes in two forms: defined and undefined, each with its own cost, its own processing time, and its own paperwork trail. Below, we break each of these down with practical tables you can bookmark for your next hire.
What Is a Certificate of Sponsorship UK?
A certificate of sponsorship UK employers assign is an electronic record carrying a unique reference number. It is not a document the worker can print and frame; it exists inside the SMS, and the worker simply quotes the number on their visa application. This applies chiefly to sponsorship under Appendix Skilled Worker, though other routes rely on similar logic.
There is a firm rule worth committing to memory: once assigned, the worker must apply for their visa within three months. They also cannot apply more than three months before the start date listed on the certificate. Miss that window, and the certificate becomes unusable, forcing the employer back to square one.
Before assigning a certificate, some employers also need to check whether their worker requires an Academic Technology Approval Scheme (ATAS) certificate, a separate clearance for certain research and technical roles. It’s worth confirming this early, since it can affect your timeline.
It’s also worth noting that a CoS UK visa route is entirely distinct from family-based permissions under Appendix FM or Appendix Family Reunion, which follow their own eligibility criteria rather than employer sponsorship. If your query sits closer to a family visa, our guide on UK family immigration rules may be more relevant. For employer-led hiring, though, a valid sponsor licence always comes first, something we cover in detail in our sponsor licence application guide for HR teams.
Defined vs Undefined Certificate of Sponsorship
Not every CoS is the same. The type you need depends entirely on where your candidate is applying from.
| Certificate Type | Who It’s For | Typical Route |
| Defined CoS | Skilled Worker applicants applying from outside the UK | Requested via SMS, tied to a specific job |
| Undefined CoS | Skilled Workers already inside the UK or applicants on most other sponsored routes | Drawn from an annual allocation estimated at licence stage |
Defined certificates are usually the more straightforward of the two, since each request relates to one named candidate and one job. Undefined certificates work differently; sponsors estimate how many they’ll need for the year when applying for their licence, then request additional ones through the SMS as hiring needs grow.
If your organisation sponsors under Global Business Mobility, as a Minister of Religion, for International Sportspersons, or under the Seasonal Worker route, the same defined-versus-undefined logic still applies, though the fee structure differs slightly (more on that below). For a broader look at eligibility across routes, our article on Skilled Worker visa employer sponsorship rules is a useful next read.
Certificate of Sponsorship Processing Time UK Employers Should Plan For
This is where recruitment plans often come unstuck. Processing time genuinely differs depending on which certificate type you’re requesting, and the figures below should be treated as a general guide rather than a guarantee; UKVI may need longer if further checks are required.
| Certificate Type | Typical Processing Time |
| Defined CoS | Usually decided within one working day |
| Undefined CoS (standard) | Usually decided within 12 weeks |
| Undefined CoS (priority service) | Can be reduced to around 5 working days, for an additional fee |
Our advice: never treat a start date as fixed until the certificate has actually been assigned. If your recruitment timeline is tight, the priority service can be worth the extra cost, but it’s not something to rely on as a default. Always check current timescales on GOV.UK before confirming a start date with a candidate, since these windows are reviewed periodically.
How to Avoid Delays When Assigning a CoS
- Keep your SMS user roles correctly assigned and up to date.
- Double-check job details, salary, and SOC code before submission.
- Confirm ATAS requirements early, where relevant.
- Avoid submitting requests at the last possible moment before a start date.
Certificate of Sponsorship UK Cost Explained
Cost is usually the first question employers ask, and understandably so; it affects every hiring decision. The certificate of sponsorship UK cost depends on the type of sponsor licence you hold, and it’s the employer, not the worker, who must pay it for most routes.
| Licence Type | Cost Per Certificate |
| Worker route (most cases) | Currently set at £525 |
| Temporary Worker route | Currently set at £55 |
| International Sportsperson (assigned for more than 12 months) | £525 |
| International Sportsperson (assigned for 12 months or less) | £55 |
These figures reflect current published rates, but Home Office fees are reviewed from time to time, so it’s always worth confirming the exact amount on GOV.UK before budgeting a hire.
Crucially, the sponsor must cover this fee themselves when sponsoring a Skilled Worker, a Global Business Mobility applicant, a Minister of Religion, an International Sportsperson, a Scale-up Worker, or a Seasonal Worker. Asking the worker to pay, or to cover any linked application costs, risks the sponsor licence being revoked.
The CoS fee is also rarely the only cost involved. Many sponsors also need to budget for the Immigration Skills Charge, a separate levy that applies per sponsored worker per year. We’ve built a dedicated resource, our Immigration Skills Charge calculator for UK employers, to help you model the fuller cost of a hire rather than budgeting the CoS fee in isolation.
Other Costs to Factor In: Certificate of Sponsorship UK
- Immigration Skills Charge — paid by the sponsor; varies by organisation size and sponsorship length.
- Visa application fee — usually paid by the worker, though employers sometimes cover it.
- Immigration Health Surcharge — an annual charge giving the worker access to the NHS.
Modelling all three alongside the CoS fee gives a far more realistic picture of what sponsoring a role actually costs your business.
Documents Required for CoS Assignment
Getting the paperwork right the first time saves weeks further down the line. Broadly, the documents required for CoS assignment fall into a few categories:
- Role details — job title, SOC code, salary, and working hours.
- Worker’s personal details — full name, date of birth, and passport information.
- Right-to-work evidence — confirming the worker’s current immigration status, where applicable.
- Qualification or English language evidence — required for certain routes or occupations.
Requirements shift slightly depending on the route. A Health and Care Worker hire, for instance, follows different evidentiary expectations to a Global Business Mobility case. If your hire falls under specific occupation criteria, our guide to eligible occupations under the Skilled Worker visa is worth reading alongside this section, and if salary thresholds are a concern, our piece on the Shortage Occupation List and salary rules breaks this down further.
A single inaccurate entry, a mismatched salary figure, or an incorrect SOC code is one of the most common causes of delay or refusal at the visa stage. It pays to have someone check the details before submission.
What a CoS Sample Typically Includes
Employers assigning their first certificate often ask what a CoS sample actually looks like. In general terms, the record includes:
- A unique reference number
- Sponsor details and licence information
- Job title and SOC code
- Salary and working hours
- Proposed start date
There’s no substitute for seeing this format explained by someone who works with it regularly, particularly for a first assignment. Our Skilled Worker Visa service supports employers through exactly this stage of the process.
Common Mistakes Employers Make When Assigning a CoS
- Requesting the wrong certificate type (defined instead of undefined, or vice versa).
- Overlooking an ATAS requirement before assignment.
- Missing the three-month application window.
- Entering an inaccurate salary or SOC code, risking refusal.
- Leaving certificate requests until the last minute before a start date.
How GMS Immigration Can Help
Sponsorship is procedural on paper, but the margin for error is real. A wrong certificate type, a missed window, or an inaccurate SOC code can unravel weeks of recruitment effort. Our team supports employers through every stage of the CoS UK visa journey, from confirming eligibility and preparing accurate SMS submissions to advising on the wider immigration services that surround sponsorship. If you’re preparing your first certificate or your business is scaling its sponsored workforce, get in touch for tailored, IAA-regulated advice before you submit.
Frequently Asked Questions About Certificate of Sponsorship UK
What is a certificate of sponsorship in the UK?
It’s an electronic record, not a physical document, that a licensed sponsor assigns to a worker so they can apply for their visa under routes such as Appendix Skilled Worker.
How much does a certificate of sponsorship cost in the UK?
Cost depends on your licence type. Current published rates sit at £525 for most Worker-route certificates and £55 for Temporary Worker routes, though these figures should always be confirmed on GOV.UK before budgeting.
How long does CoS processing take in the UK?
Defined certificates are usually decided within one working day. Undefined certificates typically take up to 12 weeks, though a priority service can bring this down to around five working days.
What is the difference between a defined and undefined CoS?
A defined CoS is for Skilled Worker applicants applying from outside the UK. An undefined CoS covers those already in the UK or applicants on most other sponsored routes.
What documents are required for a certificate of sponsorship?
Role details, the worker’s personal information, right-to-work evidence, and, in some cases, qualification or English language evidence.
Can an employer ask the worker to pay for the CoS?
No. For most sponsored routes, the employer must cover the fee themselves. Passing this cost to the worker can put the sponsor licence at risk.
Does a certificate of sponsorship guarantee a visa?
No. It allows the worker to apply, but the visa application is still assessed on its own merits against the immigration rules.
How long is a certificate of sponsorship valid for?
The worker must apply for their visa within three months of the certificate being assigned.