Certificate of Sponsorship: what it is and how it works

GOV.UK describes two kinds of Certificate of Sponsorship on the Skilled Worker route, and which one applies depends on where the worker is applying from.

• A defined CoS is for a Skilled Worker applying for entry clearance from outside the UK. The sponsor requests each defined certificate individually through the SMS, stating the job, occupation code and salary, and the Home Office considers the request before the certificate can be assigned. Published guidance states that most requests are decided within one working day, with some taking longer where further checks are made.
• An undefined CoS is for applications made from inside the UK, such as an extension, a change of employment or a switch from another route, and for the other sponsored work routes. Sponsors are given an annual allocation of undefined certificates when the licence is granted and at each renewal, and can request an increase.

For a worker, the practical difference is timing: an employer hiring from abroad must have the defined certificate approved before it can be assigned, whereas an employer with undefined certificates in its allocation can assign one straight away. GOV.UK sets out the current rules for each type.

A Certificate of Sponsorship records the facts on which the visa application is assessed. Published guidance lists the information a sponsor enters, which includes:

• the worker’s personal details, passport number and nationality;
• the job title and a summary of the duties;
• the four-digit SOC 2020 occupation code the sponsor has chosen for the role (the occupation directory lists each code with its eligibility);
• the gross annual salary, the hours per week, and any allowances the sponsor counts towards the salary;
• the start and end dates of the employment, and the work address;
• a statement that the sponsor has met the relevant requirements, including whether the Immigration Skills Charge applies;
• the sponsor’s own licence number and the certificate’s reference number.

The salary and occupation code on the certificate are what the Home Office compares with the published rules: the job must be in an eligible code and paid at or above the higher of the general threshold, £41,700 a year at the last check, and the going rate for the code. The salary threshold guide lists every going rate. Figures checked against GOV.UK on 5 Sept 2026.

The Home Office charges the sponsor a fee for each Certificate of Sponsorship it assigns, and GOV.UK publishes the current amount. Sponsor guidance is explicit that this fee, like the licence fee and the Immigration Skills Charge, is a cost of sponsorship that the sponsor must not recover from the worker, whether as a deduction, a repayment clause or a request for payment. A sponsor that does so can have its licence revoked. The worker’s own visa application fee and the Immigration Health Surcharge are separate charges payable by the applicant unless the employer chooses to cover them.

A priority service exists for sponsors who need a defined certificate decided faster than the standard timescale, with a limited number of slots released each working day. How it works is covered in Certificate of Sponsorship priority service.

The order of events is fixed by how the system works. An employer appears on the register when its licence is granted; it advertises and fills roles in the ordinary way; and only once it has offered a job to a particular worker does it create a certificate for that worker and that job. A licence is therefore a fact about the employer, which the register and the sponsor licence check can confirm, while a certificate is a fact about one offer, which only the employer can confirm. Nothing on the register says whether an employer intends to assign a certificate for a given vacancy.

That is why every listing on the jobs board is described in terms of the employer’s licence and the occupation’s eligibility, never in terms of the vacancy itself, and why the question to put to an employer is a precise one: whether it intends to assign a Certificate of Sponsorship for this role, under which occupation code, and at what salary.

• Jobs at licensed sponsors — current roles at employers matched to the Home Office register.
• UK sponsor list — every organisation permitted to assign a certificate, by town, sector and route.
• Sponsor licence check — confirm an employer against the register before relying on an offer.
• Salary threshold and going rates — the figures a certificate’s salary is measured against.