Article Overview
The Certificate of Sponsorship, or CoS, is at the centre of every Skilled Worker visa application. It is not a paper certificate but an electronic record that your UK employer creates in the Home Office sponsorship system. If the CoS is wrong, the visa can be refused even when everything else is in order. This guide explains what you should check.
What is a Certificate of Sponsorship?
A CoS is a unique reference number linked to a record that confirms a licensed sponsor is offering you a specific job. It contains the key details of the role and is used by the Home Office to check that the job meets the Skilled Worker rules. You enter the CoS reference number in your visa application.
What information does a CoS contain?
- Your personal details, exactly as in your passport.
- The sponsor's details and licence number.
- Job title and the occupation code (SOC 2020).
- A description of the main duties.
- Salary and allowances, and weekly working hours.
- Start and end dates of employment.
- Work location.
- Whether the sponsor certifies maintenance for you and your dependants.
Who can issue a CoS?
Only an employer with a valid Home Office sponsor licence can assign a CoS. You can check whether an employer is licensed on the register of licensed sponsors published on GOV.UK. If an employer asks you to pay for a CoS, treat that as a serious warning sign; the Home Office prohibits sponsors from charging workers for sponsorship costs.
How long is a CoS valid?
A CoS is valid for three months from the date it is assigned. You must apply for your visa within that period. You also cannot apply more than three months before the start date on the CoS. If the CoS expires before you apply, the employer needs to assign a new one.
Who pays for the CoS?
The sponsor pays the CoS fee and the Immigration Skills Charge. These costs cannot be passed on to the worker. You pay your own visa fee and Immigration Health Surcharge, although some employers choose to cover them.
Checking your CoS before you apply
Ask your employer to share the CoS details with you before you submit your application. Check:
- Name and date of birth match your passport exactly.
- Job title and duties describe what you will really do.
- Occupation code fits those duties and is eligible at the required skill level, usually RQF 6.
- Salary meets the general threshold of £41,700 and the going rate for the code, based on basic pay without allowances.
- Hours are consistent with the salary calculation.
- Start date is realistic given your visa timeline.
- Maintenance is certified if the sponsor has agreed to cover it.
Common CoS mistakes
- An occupation code chosen because it has a lower going rate, not because it matches the role.
- Duties copied from a generic job description that do not match your experience.
- Salary that includes allowances which the Home Office does not count.
- Spelling mistakes in names or passport numbers.
- An expired CoS by the time you apply.
Small errors can sometimes be corrected with a sponsor note, but significant errors usually require a new CoS.
What happens after the visa is granted?
The sponsor must keep records about you, report certain changes to the Home Office and pay you at least the salary stated on the CoS. If you change jobs to a different employer, the new employer must assign a new CoS and you must apply to update your permission.
How ZANS Consultants can help
We review your CoS details against the Skilled Worker rules before you apply, and support employers with sponsor duties. Learn more about our UK Skilled Worker visa service and our UK Sponsor Licence service, read our step-by-step application guide, or book a consultation.
General information only: sponsorship rules and fees change. Check the current GOV.UK guidance before you apply. The Home Office makes the final decision on every application.
