Certificate of Sponsorship
Certificate of Sponsorship explained, what a Skilled Worker applicant should know
A Certificate of Sponsorship, usually called a CoS, is an electronic record assigned by a licensed sponsor to a worker. It is not a paper certificate and it does not replace the visa application.
Last reviewed 21 October 2026
Key points
- A Certificate of Sponsorship is an electronic record with a unique reference number.
- For a Skilled Worker applying from outside the UK, the sponsor normally uses a defined Certificate of Sponsorship.
- The worker normally needs to use the CoS for the visa application within three months of assignment.
- For Skilled Workers, GOV.UK says the sponsor must pay the Certificate of Sponsorship fee and must not ask the worker to pay it.
What the Certificate of Sponsorship does
The sponsor assigns the electronic record through the sponsorship management system. The worker receives the reference number used in the visa application.
The CoS records information about the sponsored employment, but the visa application is still considered separately under the immigration rules.
Defined certificates for overseas Skilled Workers
GOV.UK states that defined Certificates of Sponsorship are used for people applying for a Skilled Worker visa from outside the UK.
The sponsor requests and assigns the certificate through its sponsorship system.
Who pays the CoS fee
The sponsor must pay the Certificate of Sponsorship fee for a Skilled Worker. GOV.UK warns that a sponsor licence may be revoked if the sponsor asks the sponsored worker to pay that fee or costs linked to the sponsor application.
A demand for money specifically to buy or obtain a Certificate of Sponsorship should therefore be treated as a serious warning sign.
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Official sources
Rules and public datasets can change. Use the official source when making a current decision.