What Is a Certificate of Sponsorship?
A Certificate of Sponsorship (CoS) is an electronic record — not a physical document — issued by a licensed sponsor through the Sponsor Management System (SMS). It confirms details of the sponsored role and gives the worker a unique reference number they need to apply for their visa. Without a CoS from an A-rated sponsor, a worker cannot submit a qualifying application under most sponsored routes.
Defined vs Undefined CoS
| Type | Used For |
|---|---|
| Defined CoS | Workers applying for entry clearance from outside the UK |
| Undefined CoS | Workers already in the UK switching into or extending a sponsored route |
What a CoS Must Include
- The worker's personal details and passport information
- Job title, SOC (occupation) code, and a description of duties
- Salary, matched against the applicable minimum salary and going rate for the role
- Start date and, where relevant, end date of employment
- Confirmation the role meets the skill level required for the route
Every detail on the CoS must accurately reflect the actual role. A mismatch between the CoS and the worker's real duties or salary is a compliance breach, not just a paperwork error, and can put the sponsor's licence at risk.
Cost and Validity
- Worker route CoS: £525 per worker
- Temporary Worker route CoS: £55 per worker (some categories exempt)
- A CoS must generally be used by the worker to apply within a set period after assignment — check current UKVI guidance for the exact route-specific window before assigning
Common CoS Mistakes
- Assigning a CoS with a SOC code that doesn't match the actual duties of the role
- Salary stated on the CoS falling below the current going rate or minimum threshold for the occupation
- Assigning defined CoS to a worker already in the UK, or vice versa
- Failing to report changes to the role after the CoS is assigned, where the worker's actual circumstances change before their visa is granted
Solicitor's Insight
CoS errors are one of the most common triggers for individual visa refusals and, cumulatively, for sponsor compliance action. We check SOC code selection and salary compliance against current thresholds before every CoS is assigned, not just at the point of the original licence application.
Frequently Asked Questions
What is the difference between a defined and undefined CoS?
A defined CoS is for workers applying from outside the UK; an undefined CoS is for workers already in the UK switching or extending into a sponsored route.
How much does a Certificate of Sponsorship cost?
£525 for most Worker route CoS (such as Skilled Worker) and £55 for most Temporary Worker route CoS, with some Temporary Worker categories exempt.
Can I assign a CoS with an incorrect salary and correct it later?
Errors on an assigned CoS can cause the worker's visa application to be refused and can amount to a sponsor compliance breach — always verify SOC code and salary against current thresholds before assigning.
Does the sponsor or the worker pay for the CoS?
The sponsoring employer pays the CoS fee, not the worker.