CoS Expiry & Validity
A Certificate of Sponsorship is valid for 3 months from the date it is assigned. If a worker does not submit their visa application within this window, the CoS expires and the employer must issue a new one.
In This Article
- How long is a CoS valid?
- What happens if the CoS expires?
- Does CoS expiry affect the visa duration?
- CoS start dates and job start flexibility
- Common causes of CoS expiry issues
- What employers should do to avoid problems
- Common mistakes to avoid
- Frequently asked questions
- Related terms
How Long is a CoS Valid?
A Certificate of Sponsorship is valid for 3 months from the date it is assigned by the employer. Not 3 months from the visa application. Three months from the moment the employer clicks "assign" in the Sponsorship Management System.
The worker must submit their visa application before this window closes. If the CoS has expired, the visa application system will reject the reference number.
This validity period applies to both Defined CoS and Undefined CoS.
CoS Application Deadline Calculator
A Certificate of Sponsorship is valid for 3 months. Enter your assignment date to find your visa application deadline.
You must submit your visa application (not just prepare it) before this date.
What Happens if the CoS Expires?
If the worker fails to submit their visa application within the 3-month validity window:
- The CoS is marked as expired in the SMS
- It cannot be reactivated or extended
- The employer must issue a new CoS, consuming allocation again
- For Defined CoS, a new Home Office approval may be needed, adding further delay
- The worker must start their application afresh using the new CoS reference
This happens more often than you might think. International candidates juggling travel logistics, document gathering, or personal emergencies can easily miss the window.
Does CoS Expiry Affect the Visa Duration?
No. The CoS's 3-month validity and the visa duration are separate things. Once a visa application is submitted using the CoS, the CoS has done its job. Your visa length depends on the start and end dates recorded on the CoS for the role, and the maximum leave grant for the route (up to 5 years for Skilled Worker).
If a CoS expires and a new one is issued, the new CoS dates govern the visa. Changed start date on the new CoS? The worker's visa will reflect those updated dates.
CoS Start Dates and Job Start Flexibility
The CoS records a job start date. You can apply for a visa at any point within the 3-month validity window. There is no requirement to apply the moment it is assigned. However:
- The visa, if granted, will typically be issued with leave starting around the date of grant (not necessarily the CoS start date for entry clearance)
- Workers granted entry clearance can arrive in the UK up to 14 days before the CoS start date
- Workers should not start working before the CoS start date
If the job start date on the CoS needs to change because the role is delayed, the employer must withdraw the original CoS and issue a new one with the correct start date.
Common Causes of CoS Expiry Issues
Documents often take longer than expected to gather: police certificates, translated documents, reference letters. Biometric appointment backlogs make things worse, especially in countries where UKVCAS slots are scarce. Sometimes the worker decides not to proceed and the employer only finds out weeks later.
Other common causes include employers assigning the CoS too early (before the worker is ready to apply), personal emergencies on the worker's side, and bank statement shortfalls where the worker fails the financial maintenance test on first attempt and needs more time to save.
What Employers Should Do to Avoid Problems
- Coordinate timing with the worker. Before assigning a CoS, confirm they have all documents ready and understand the 3-month window.
- Assign the CoS as late as reasonably possible. Start date 4 months away? Wait until 8-10 weeks before the target application date.
- Set a reminder 4 weeks before expiry. If the worker has not applied by then, there is still time to nudge or issue a new CoS.
- Keep allocation headroom. Make sure you have enough Undefined CoS allocation to re-issue if needed. Do not allocate your last CoS to a candidate who has not committed.
Common Mistakes to Avoid
Assigning a CoS the moment the contract is signed is a frequent error. If the start date is months away, you are burning the validity window for no reason. Similarly, many employers never confirm that the worker has actually submitted their application, and only discover the CoS expired when chasing for a progress update weeks later.
On the financial side, re-issuing a CoS means paying the Immigration Skills Charge again if the original was already paid for an expired CoS (though ISC refund rules apply in some circumstances). And when you do issue a replacement, review every detail on the new CoS, including dates, salary, and SOC code, to make sure they are still current.
Frequently Asked Questions
Can a CoS be extended beyond 3 months?
No extension mechanism exists. You withdraw the expired CoS and issue a fresh one. That is the only path.
Is the Immigration Skills Charge refunded if a CoS expires unused?
If the employer withdraws the CoS before anyone uses it for a visa application, UKVI will refund the ISC. For a CoS that simply expired without withdrawal, a refund may still be possible, but you will need to contact UKVI directly.
What if the visa is still being processed when the CoS start date arrives?
This happens regularly and is not a problem. The CoS start date is an intended date, not a hard deadline. The Home Office assesses applications based on the CoS that was valid at the time of submission, not at the time of decision.
Can a worker reuse a CoS if their application was refused?
No. Each CoS is consumed the moment a visa application is submitted, regardless of the outcome. Refused? The worker needs a brand new CoS to reapply.
Related Terms
- Certificate of Sponsorship
- Defined CoS vs Undefined CoS
- Immigration Skills Charge
- Changing Visa Sponsors
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