What is a Certificate of Sponsorship?
A Certificate of Sponsorship (CoS) is a virtual document, not a physical certificate, that a UK employer creates using the Home Office's Sponsorship Management System (SMS). It contains a unique reference number that you, the visa applicant, include in your Skilled Worker visa application.
Think of the CoS as the employer's formal confirmation to the Home Office that they are offering you a genuine role that meets all the requirements of the visa route. Without a valid CoS, you cannot apply for a Skilled Worker visa.
Key Information on a CoS
- Unique reference number (used in your visa application)
- Job title, SOC code, and skill level
- Annual salary and any allowances
- Start date and working hours
- Employer's sponsor licence number
- Whether the role is on the Temporary Shortage List
Defined vs undefined Certificate of Sponsorship
There are two types of Certificate of Sponsorship, and understanding the difference is critical: they are used in different circumstances and have different allocation rules.
Defined CoS
- Used for applicants applying from outside the UK
- Requires prior approval from the Home Office
- The employer must request an allocation of defined CoS certificates annually
- The role must meet a minimum salary of £41,700 (or the going rate for the SOC code, whichever is higher)
- Typically used for initial visa applications from abroad
Undefined CoS
- Used for applicants already in the UK (extending or switching)
- Does not require prior Home Office approval
- Can be assigned directly from the employer's SMS allocation
- Also used for in-country changes of employer
- Faster process, with no pre-approval waiting period
CoS fees: the £525 assignment fee
The CoS assignment fee is paid by the employer, not the applicant. Employers must also hold a valid sponsor licence and may need to pay the Immigration Skills Charge. Current sponsorship fees are published on GOV.UK.
| Fee Type | Amount |
|---|---|
| CoS assignment fee | Check GOV.UK |
| Sponsor licence fee | Check GOV.UK |
| Immigration Skills Charge | Check GOV.UK |
How employers assign a CoS
Hold a valid sponsor licence
The employer must already be a licensed sponsor. If not, they apply via the Home Office (takes 8+ weeks).
Run a Resident Labour Market Test (if applicable)
For some roles, the employer must advertise the position to settled workers first. Many roles are now exempt.
Log in to the Sponsorship Management System
The employer's authorising officer or key contact accesses the SMS portal.
Assign the CoS to the applicant
The employer enters the job details, salary, SOC code, and the applicant's personal information.
Pay the £525 fee
The fee is deducted from the employer's SMS account balance.
Share the reference number with the applicant
The applicant uses this number in their visa application. The CoS is valid for 3 months.
Common reasons for CoS refusal
- Role below minimum skill level: The position must meet the current Skilled Worker skill requirement or qualify under an eligible exception.
- Salary below threshold: The salary must meet the applicable general threshold and the going rate for the SOC code.
- Employer's CoS allocation exhausted: Employers have annual allocations. If exceeded, they must request more from the Home Office.
- Genuine vacancy test failure: The Home Office may question whether the role is a genuine vacancy or created primarily for immigration purposes.
- Compliance issues: Employers with a history of non-compliance or poor HR records may be refused.
Frequently asked questions
What is a Certificate of Sponsorship (CoS)?
A CoS is a virtual document, not a physical certificate, issued by a UK employer through the Sponsorship Management System (SMS). It contains a unique reference number that the visa applicant uses in their application. The CoS records the job details, salary, and working conditions.
How much does a CoS cost the employer?
The CoS assignment fee is paid by the employer, not the visa applicant. Employers must also hold a valid sponsor licence and may need to pay the Immigration Skills Charge. Current sponsorship fees are published on GOV.UK.
How long is a CoS valid?
A CoS is valid for 3 months from the date of assignment. The visa application must be submitted within this period. If it expires before use, the employer must assign a new one.
Can a CoS be transferred to another employer?
No. A CoS is specific to the employer who assigned it. If you change jobs, the new employer must assign a fresh CoS and you must submit a new visa application (or change of employment application if already in the UK).
What are common reasons for CoS refusal?
Common reasons include: the role does not meet the applicable skill level, the salary is below the threshold, the employer has exhausted their CoS allocation, or the Home Office suspects the role is not genuine.