Defined vs undefined at a glance
Defined CoS
Skilled Worker applying from outside the UK. Requested one at a time; usually approved in 1 working day.
Undefined CoS
Skilled Worker applying from inside the UK, and every other route. Drawn from your annual allocation.
Before you assign it
Check the salary on the certificate meets the minimum for the occupation code. Use the minimum salary calculator, then work out the full cost.
Frequently asked questions
What is the difference between a defined and an undefined CoS?
A defined certificate of sponsorship is for a Skilled Worker applying from outside the UK, and you apply for each one individually. An undefined CoS is for Skilled Workers applying from inside the UK and for all other routes, and comes from your annual allocation.
How long does a defined CoS take?
Defined CoS requests are usually approved within one working day, but can take longer if UKVI needs to make further checks on the role.
How long is a certificate of sponsorship valid?
Once assigned, the worker must use the CoS to apply for their visa within 3 months. They also can’t apply more than 3 months before the job start date on the certificate.
How does the annual CoS allocation work?
For most sponsors the CoS year runs for 12 months from the date the licence was granted. A-rated sponsors with automatic renewal get an allocation equal to the number of CoS they assigned in the previous year. You can request more at any time.
How much does a CoS cost?
A certificate of sponsorship costs £525 for Worker routes such as Skilled Worker, and £55 for Temporary Worker routes. The Immigration Skills Charge is paid at the same time.
Official sources
Rules and fees checked September 2026. Immigration rules change often — this tool gives general information, not legal or immigration advice. For advice on an individual case, speak to a regulated immigration adviser or one of the firms listed here.