Who needs a Certificate of Sponsorship?

Any non-UK / non-Irish national applying under the Skilled Worker route, Senior or Specialist Worker route, Health and Care Worker visa, Scale-Up route, or most other Worker routes needs a CoS assigned by a licensed sponsor before they can apply. The sponsor must hold a current sponsor licence in the correct category.

How long is a Certificate of Sponsorship valid for?

A CoS is valid for 3 months from the date it is assigned. The worker must submit their visa application within that window or the CoS expires and a new one must be assigned (and paid for). The 3-month clock starts the moment the CoS is assigned in the SMS, not the moment the worker accepts the job.

How much does a Certificate of Sponsorship cost in 2026?

From April 2024 the CoS fee for Worker routes is £239 per certificate, paid at the point of assignment. On top of that, sponsors pay the Immigration Skills Charge — £1,000 per year per worker for medium and large sponsors, £364 per year for small or charitable sponsors — for the full length of the CoS, payable up front and non-refundable if the worker leaves early. Government fees are reviewed periodically; always confirm the current figure on gov.uk before quoting.

What is the difference between a Defined and Undefined CoS?

A Defined CoS is for Skilled Workers applying for entry clearance from outside the UK — sponsors request each one individually and the Home Office decides whether to grant it. An Undefined CoS covers in-country switches, extensions, and most other Worker routes — it comes out of the sponsor's annual allocation and does not need a separate Home Office request. See our dedicated Defined vs Undefined CoS guide.

Can a Certificate of Sponsorship be withdrawn?

Yes. A sponsor must withdraw a CoS in the SMS if the job offer is withdrawn, the worker does not start, or the role materially changes before the visa is granted. If the visa has already been granted, the sponsor instead reports the change (salary cut, role change, early leaver, absence) using the reporting tools in the SMS — see the reporting deadlines guide.

What does UKVI check about CoS at audit?

UKVI inspectors check that every assigned CoS is supported by a genuine vacancy, an accurate SOC code, salary at or above the threshold for that code, a signed contract, and right-to-work evidence held on the worker's file. Mis-assigned or unsupported CoS are one of the most common reasons sponsor licences are downgraded or revoked.

Certificate of Sponsorship (CoS) — UK Guide

A Certificate of Sponsorship (CoS) is the electronic record a UK sponsor licence holder issues to a worker so the worker can apply for a visa. Despite the name, it is not a physical certificate — it is a unique reference number generated in the Home Office Sponsorship Management System and sent to the worker.

Every Skilled Worker, Health & Care Worker, Senior or Specialist Worker, Scale-Up and most other Worker-route applicants need a CoS before they can submit a visa application. This guide covers what a CoS contains, the Defined vs Undefined split, costs, validity, and the points UKVI checks at audit.

What a Certificate of Sponsorship contains

When you assign a CoS in the SMS you commit, on the sponsor's behalf, to a specific job for a specific person. The record includes:

The worker's personal details and passport information.
The SOC 2020 occupation code for the job.
Job title, main duties, hours per week, and work address(es).
Gross annual salary and how it is paid.
Start and end dates for the period of sponsorship.
Confirmation the role meets the skill and salary thresholds for the route.

Once assigned, the CoS cannot be edited. If anything material changes before the visa is granted, the CoS must be withdrawn and a new one assigned — and paid for again.

Defined vs Undefined CoS

The Home Office splits CoS into two categories:

Defined CoS — for Skilled Workers applying for entry clearance from outside the UK. Sponsors request each Defined CoS individually through the SMS and the Home Office decides whether to grant it (usually within one working day).
Undefined CoS — for in-country switches, extensions, and most other Worker routes including Health & Care, Senior or Specialist Worker, and Scale-Up. Undefined CoS come out of the sponsor's annual allocation — request more in the SMS if the allocation runs low.

Full breakdown, including the common mis-assignment scenarios, in our Defined vs Undefined CoS guide.

Costs in 2026

Two government fees attach to every CoS at assignment:

CoS fee — £239 per certificate for Worker routes (from April 2024), payable at the point of assignment. Confirm the current figure on gov.uk before quoting.
Immigration Skills Charge (ISC) — £1,000 per worker per year for medium and large sponsors; £364 per worker per year for small or charitable sponsors. ISC is paid up front for the full length of sponsorship on the CoS and is non-refundable if the worker leaves early.

Visa application fees and the Immigration Health Surcharge are paid by the worker, not the sponsor — though many sponsors choose to reimburse them as part of the offer.

How long a CoS is valid

A CoS is valid for 3 months from the date it is assigned. The worker must submit their visa application within that window. If the 3 months pass, the CoS expires automatically and a new one must be assigned and paid for from scratch. The 3-month clock starts the moment the CoS is assigned in the SMS — not the moment the offer is accepted.

How a CoS is assigned

A Level 1 or Level 2 User signs in to the SMS at points.homeoffice.gov.uk.
For an out-of-country Skilled Worker, request a Defined CoS; otherwise draw from the Undefined CoS allocation.
Enter the worker's details, SOC code, salary, hours, and start / end dates.
Pay the CoS fee and the relevant Immigration Skills Charge.
Send the CoS reference number to the worker, who uses it on the visa application.

What UKVI checks about CoS at audit

Mis-assigned or unsupported CoS are one of the most common reasons UKVI downgrades or revokes a licence. At audit, inspectors typically check:

The role on the CoS matches the worker's actual day-to-day duties.
The SOC 2020 code is appropriate for those duties — not chosen for convenience.
The salary on the CoS is at or above the threshold for that SOC code and route.
A signed contract is on file matching the CoS terms.
Right-to-work evidence is held in line with Appendix D record-keeping requirements.
Any changes since the CoS was assigned have been reported within the deadlines in our reporting deadlines guide.

Common CoS mistakes

Assigning before the role is genuinely confirmed. The 3-month CoS clock runs whether the worker is ready or not.
Using the wrong SOC code to hit a lower salary threshold — a frequent revocation trigger.
Not paying enough Immigration Skills Charge for the full sponsorship period on the CoS.
Failing to withdraw a CoS when the worker pulls out before applying.
Forgetting to report a salary or role change after the visa is granted — this happens at the worker file, not on the CoS itself.