Certificate of Sponsorship (CoS): An HR Manager's Guide to Getting It Right

Key Takeaways

• A Certificate of Sponsorship (CoS) is a unique digital reference, not a physical document, that a licensed sponsor assigns to a worker so they can apply for a sponsored UK work visa.
• A CoS is not a visa and does not guarantee one. The worker must still meet every visa requirement, and the details on the CoS must match their application exactly.
• For Worker licences there are two types: a Defined CoS for Skilled Worker applicants applying from outside the UK, which UKVI assesses before allocation, and an Undefined CoS for in-country switches, extensions and other routes, assigned from your annual allocation. Temporary Worker routes use a separate CoS.
• Timing is strict. A CoS must be used within three months of assignment, the worker cannot apply more than three months before the job start date, each CoS supports only one application, and a CoS can never be transferred to another worker.
• The SOC occupation code and salary are the highest-risk entries. They drive the going rate, the skill level and whether the role qualifies at all, and errors are a leading cause of refusals and licence investigations.
• Sponsorship costs must be met by the employer and never passed to the worker: the CoS fee is £525 for a Worker CoS and £55 for a Temporary Worker CoS, plus the Immigration Skills Charge and licence fees.
• The Home Office treats CoS errors as a compliance signal. A single mistake can prompt it to examine your wider CoS history and move to downgrade, suspend or revoke the licence.
• Assigning and tracking certificates is far safer with the right systems. WPC HR's compliance software keeps CoS details, contracts and payroll aligned, tracks validity and reporting deadlines, and flags salary and SOC risks, while our Sponsor Licence Compliance Audit reviews your CoS practices before UKVI does.

Introduction

The Certificate of Sponsorship is where sponsorship becomes real. Everything the Home Office scrutinises about a sponsored hire, the genuineness of the role, the occupation code, the salary, the worker's details, is captured on the CoS, and by assigning it you are certifying to the Home Office that all of it is correct. It is, in effect, a formal self-certification, and the Home Office treats errors accordingly.

For HR managers, that makes the CoS both routine and high-stakes. The mechanics of assigning one on the Sponsor Management System take only a few minutes, but a wrong SOC code, a salary below the threshold, a mistyped passport number or the wrong type of certificate can lose you the candidate, waste the fees you have already paid, and open the door to a wider compliance investigation. In 2026, with sponsor enforcement at record levels, getting the CoS right the first time matters more than ever.

This guide is a practical, end-to-end reference for HR teams: what a CoS is and which routes need one, the difference between Defined and Undefined certificates, how to get the SOC code and salary right, how to request and assign a CoS step by step, the 2026 costs, and how to handle corrections, withdrawals and refusals. For further background, see our group's guides on what employers should know about the CoS and on checking whether a CoS is genuine.

What Is a Certificate of Sponsorship?

A Certificate of Sponsorship is a digital record held on the UKVI system, identified by a unique reference number. Despite the name, there is no certificate to print. The reference number is what the worker enters on their visa application, and it links their application to the job you have offered and the confirmations you have made about it. The official overview is on GOV.UK at Certificates of Sponsorship for employers.

The record contains the job title, SOC occupation code, salary, start date, hours and location, along with the worker's personal and passport details. By assigning it, you confirm to the Home Office that the role and the worker meet the requirements of the relevant visa route. Two points are worth fixing in mind from the outset. First, a CoS is not a visa; it only allows the worker to apply, and they must still satisfy every other requirement such as English language, finances and the genuineness of the role. Second, the details you enter become the basis of the decision, so they must match the contract, the payroll and the visa application precisely.

Which Visa Routes Need a Certificate of Sponsorship?

A CoS is required for the sponsored Worker and Temporary Worker routes. It is not needed for unsponsored routes or for people who already have the right to work in the role. The table below covers the most common cases.

The Two Types of CoS: Defined and Undefined

Since the December 2020 rule changes, employers with a Worker licence use two types of certificate. Choosing the wrong one is a common and avoidable error, because it delays the whole process. A separate certificate applies under a Temporary Worker licence.

The practical distinction is location and status. If the worker is overseas and applying as a Skilled Worker, you need a Defined CoS. If they are already in the UK and switching or extending, or applying under another route, you need an Undefined CoS. Do not be tempted to route a role through a lower-fee Temporary Worker certificate to save money, as mismatches of this kind are exactly what invites additional scrutiny.

Before You Assign: Eligibility and the Genuine Vacancy Test

A CoS should only ever be assigned once you are confident both the sponsor and the worker meet the requirements. On the sponsor side, you need a valid licence of the right type, an A-rating for Defined CoS requests, and a clean compliance record. On the worker side, the role must sit at the right skill level, meet the salary threshold and going rate, fall under an eligible SOC code, and represent a genuine vacancy.

The genuine vacancy test deserves particular attention because it is where credibility is won or lost. The role must be a real job your business genuinely needs, with duties that match the occupation code and correspond to how the organisation actually operates. Roles that appear inflated, artificially created to fit a candidate, or inconsistent with your size and trading activity are treated as non-genuine, and this is an area caseworkers probe closely. It is also worth checking, before assignment, whether the role needs an Academic Technology Approval Scheme (ATAS) certificate, as some scientific and technical roles do.

A useful mindset is to treat every CoS request as a compliance checkpoint. You are asking the Home Office for permission to sponsor this specific worker, so before you submit, confirm that salary, duties, hours, location and skill level are all correct and evidenced. It is far easier to get it right before submission than to recover from a refusal.

Getting the SOC Code and Salary Right

If there is one section of this guide to read twice, it is this one. The occupation code and salary are the entries most likely to cause a refusal, and they are linked, because the code determines the going rate you must meet.

Choosing the SOC occupation code

The Standard Occupational Classification code describes the role, sets its skill level, and drives the published going rate. It is the single most consequential entry on the CoS. The code must genuinely reflect the day-to-day duties of the job, not simply the job title, and never the code whose going rate happens to be most convenient. If the real work does not match the code, both the salary basis and the eligibility of the role fall away. Match the duties to the code descriptions in Appendix Skilled Occupations, which also publishes the going rates.

Meeting the salary requirement

For most Skilled Worker roles the salary must meet the higher of the general threshold, currently £41,700 a year, and the going rate for the occupation code. Some routes, new entrants and transitional cases have different thresholds, so the applicable figure must be checked against Appendix Skilled Worker for that individual rather than assumed. Remember too that from 8 April 2026 the required salary must be met in every individual pay period, not just as an annual average, so a role sitting close to the threshold leaves little room for unpaid leave, reduced hours or deductions.

Only guaranteed basic gross pay counts towards the threshold. Bonuses, unguaranteed allowances, overtime and benefits in kind generally do not, and deductions that recoup business costs or sponsorship fees from the worker are subtracted from the salary the Home Office recognises. Build the figure carefully before it goes on the CoS.

How to Request and Assign a CoS: Step by Step

The process runs through the Sponsor Management System and differs slightly depending on the certificate type. The outline below covers the Skilled Worker journey most HR teams follow.

Requesting a Defined CoS (overseas Skilled Worker)

1. A Level 1 or Level 2 user signs in to the SMS and selects Defined CoS from the Workers screen.
2. Choose to apply for a Defined CoS, select the category and enter the number required.
3. Enter the employment details, including job title, SOC code, salary and start date, then check them carefully.
4. Confirm you have read and understood the terms, and submit. UKVI usually decides within one working day.
5. Once approved, the Defined CoS appears in your SMS account ready to assign to the worker.

If a decision takes longer than the one working day standard, do not withdraw and resubmit, because that resets the review and pushes your timeline back. A delay usually means the case is being examined, so wait or respond to any evidence request promptly.

Assigning the CoS

1. From the Workers screen, select Create and Assign, then the relevant visa category.
2. Enter the employment details and save, then verify everything on the confirmation screen.
3. Select Assign, confirm the details are correct, and accept the declaration.
4. Pay the CoS fee and, where applicable, the Immigration Skills Charge.
5. The CoS is assigned and given a unique reference number. Share that number with the worker for their visa application.

For an Undefined CoS the same assignment path applies, drawing on your annual allocation rather than a pre-approved Defined certificate. If your allocation runs low, request more through the SMS in good time so onboarding is not held up.

Validity, Single Use and the Rules You Cannot Break

A handful of hard rules govern how a CoS can be used. Breaking any of them causes problems ranging from an expired certificate to a serious breach of sponsor duties.

Certificate of Sponsorship Costs in 2026

Sponsoring a worker carries several costs, all of which the employer must bear. None of them may be passed to the worker, whether directly, by deduction or through a clawback clause, and the Home Office reviews employment documents specifically to check for this.

Two cost mistakes recur. The first is misclassifying your organisation as small when it is large, or vice versa, which can cause an application to be rejected outright. The second is overlooking the Immigration Skills Charge in budgeting, then being surprised at the point of assignment. The Immigration Skills Charge applies to Skilled Worker and Senior or Specialist Worker sponsorship, and the current rates are set out in the Home Office guidance on the Immigration Skills Charge.

Correcting, Withdrawing and Cancelling a CoS

Mistakes and changes happen, and how you handle them matters. For a very minor issue such as an obvious typo, a sponsor note added through the SMS can sometimes clarify the position, but sponsor notes cannot be used to make substantive changes and should be used with caution. Where a detail is materially wrong, the safer course is usually to withdraw the incorrect CoS and assign a new, correct one, paying the fee again, rather than trying to patch it.

An assigned CoS should be withdrawn through the SMS where it is no longer needed, for example if the worker does not take up the role, leaves before applying, or the circumstances change. As a general rule, a CoS that is no longer valid or required should be dealt with promptly rather than left live, because a stale or inaccurate certificate is itself a compliance risk. Keep an internal note of any correction, withdrawal or cancellation so your records explain what happened and why.

What Happens If a CoS Is Rejected or Refused?

Problems surface at different points depending on the certificate type. A Defined CoS can be rejected at the request stage, before you ever assign it, usually because UKVI has concerns about the role, the salary, funding or genuineness, or because the request does not match your wider SMS records. Without an approved Defined CoS the worker simply cannot apply, and employers often lose the candidate along with the recruitment costs already spent.

An Undefined CoS is not pre-approved, so issues tend to appear later, either when the visa is decided or during a compliance audit. Common triggers are salary figures that fall short, role descriptions that do not match the occupation code, and discrepancies in hours or start dates. A refusal at that stage is more disruptive still, because contracts may already be signed and onboarding planned.

In both cases, the compliance dimension is the one to watch. The Home Office reads CoS problems as a possible sign of wider control weaknesses and may examine your historic assignments to judge whether the issue is isolated or systemic. If you hit a rejection or refusal, resist the urge to resubmit quickly. Understand the reason, reassess the role against the current rules, correct any record-keeping gaps, and only then proceed, ideally with a second-person or specialist review.

Common CoS Mistakes and How to Avoid Them

A single, simple control catches most of these: a second-person review of every CoS before it is assigned, checking the SOC code, salary, dates and worker details against the underlying documents. Combined with an internal audit trail on each certificate, it is the most effective way to prevent avoidable refusals.

How Can WPC HR Help?

Most CoS problems come down to details getting out of step: a SOC code that does not match the duties, a salary that dips below the going rate, a certificate that expires unused, or a change that never gets reported. WPC HR's HR compliance software keeps the moving parts aligned by holding each worker's CoS details alongside their contract, payroll and right to work evidence, tracking validity windows and reporting deadlines with automated alerts, and surfacing salary and status risks on a single compliance dashboard. If you would like a specialist to review how your certificates are being assigned and recorded before UKVI does, our Sponsor Licence Compliance Audit checks your CoS practices and wider sponsor files against current guidance and gives you a prioritised plan to fix any gaps.

📞 Call us: 020 8087 2343
📅 Book a free compliance audit: wpchr.co.uk/sponsor-licence-compliance-audit
🔗 See the platform: wpchr.co.uk/hr-compliance-software-features

Conclusion

The Certificate of Sponsorship looks like a short online form, but it is really a formal statement to the Home Office that a specific role and a specific worker meet the rules. That is why so much rests on getting it right: the correct type of certificate, an occupation code that genuinely fits the duties, a salary that clears both the threshold and the going rate in every pay period, accurate worker details, and assignment within the validity window. Each of these is straightforward on its own, and each is a common cause of refusal when it is rushed.

The sponsors who handle CoS well build in a simple discipline: check before you submit, have a second person review every certificate, keep the CoS, contract and payroll consistent, and report changes on time. Do that, and the CoS becomes a routine, low-risk step in your hiring process rather than a trigger for refusals and investigations. Where you want systems to keep the details aligned and an expert eye on your process, WPC HR can help you assign with confidence and stay compliant long after the certificate is issued.

Glossary