How to apply for a Certificate of Sponsorship extension
When a Skilled Worker visa holder approaches the end of their visa (permission to stay) and their contract is being extended, they need to apply for a visa extension. For this, their department or college should contact the Staff Immigration Team (SIT) to apply for a Certificate of Sponsorship extension.
To be considered for an extension, applicants must be continuing to work in the same or similar job. For example, a Postdoctoral Research Assistant coming to the end of their current visa may switch from one department to take up a new research post in another department without the need for the department to show that they have advertised the post. Such circumstances will be considered an extension rather than a new application.
If a Skilled Worker visa holder is moving onto a new role of similar type before the end of the current visa, their department or college should submit a Changes and Leavers Form (below) to SIT, who will notify the Home Office of this. Once the change has been reported, a Certificate of Sponsorship extension application may be submitted with the new role's details.
To apply for a Certificate of Sponsorship for an extension applicant, the employing department or college needs to download a Skilled Worker CoS extension application form (below), complete it, and return it to SIT together with the documentation listed at the end of the form.
Extensions for applicants who currently hold a Tier 2 (General) visa
To request a CoS for extending a Tier 2 (General) visa, please complete the Skilled Worker CoS extension application form as above.
As long as the extension application is made prior to 1 December 2026, the salary can also included permitted allowances, such as a housing allowance. The individual must be with the same sponsor and the allowances must be guaranteed to be paid for the duration of the extension.
Individuals who were sponsored under Tier 2 prior to 24 November 2016, and are making an extension application prior to 24 May 2023, must be paid a salary of £20,800 or above, or at least the going rate for the occupation code, if higher.
Tier 5 visa holders who have spent less than two years in the UK and need more time to finish their research can apply to have their visa (permission to enter/stay) extended up to the maximum of two years per visit. They must still meet the Home Office's Tier 5 requirements.
As the total length of stay allowed on a Tier 5 visa at any one time is two years, the length of the extension will depend on the length of time already spent in the UK on this visa. After the two years have come to an end, the sponsored researcher will be required to leave the country. If a new extension is required, they must apply from overseas. There is no limit to the number of Tier 5 visas held, as long as each individual visit does not exceed two years.
Requirements for a Tier 5 Certificate of Sponsorship extension application:
Details of the visit must remain the same as the original Certificate of Sponsorship (activities, work location, title, etc.). The amount of funding can vary, as long as it still meets the minimum national wage rate.
The sponsored researcher must continue working on the same research which their Tier 5 visa was issued for.
The hosting department/college needs to submit a Certificate of Sponsorship extension application approximately three months before the current visa expiry date. This includes a completed application form (below), confirmation of funding available and an updated project plan.
Since a Tier 5 visa is granted specifically for the purpose of the research visit in question, it is not possible to switch for the purpose of carrying out other research or switching host department or college. If a different project with a different host department or college is proposed, or if the visa holder needs to change sponsors (i.e. move to another university), they would need to leave the UK and apply for a new Tier 5 visa from overseas.
Certificate of Sponsorship extension applications should be submitted to the Staff Immigration Team (SIT) between eight to twelve weeks before the applicant's current visa expires.
Visa extension applications can be submitted to the Home Office up to three months before the current visa end date. While awaiting the outcome of their application, visa holders cannot travel, even if they have retained their original documents or have received them back from the Home Office. Leaving the UK while an active application is in progress will automatically result in the application being withdrawn.
An applicant must apply to the Home Office for permission to stay (visa):
Before their existing visa expires. By submitting a valid application before their visa expires, their current immigration status is extended until a decision is made on the application. If their visa expires whilst their application is pending, this prevents them from becoming an overstayer
Within three months of the date when their Certificate of Sponsorship (CoS) was issued. After this period the CoS will automatically expire and can no longer be used to support a visa application
SIT aims to send a reminder to departmental administrators approximately 12 weeks before an applicant's visa expires. It is the responsibility of the department and the applicant to ensure that they apply for a Certificate of Sponsorship in plenty of time.
PLEASE NOTE: Travel outside the UK is not possible while a visa application is being processed
Applicants must not travel outside of the UK until they have received a decision on their application. If they travel outside the ‘Common Travel Area’ (UK, Ireland, Isle of Man, Guernsey and Jersey) before a decision is made on the application, the application will be treated as withdrawn. Applicants should therefore allow around 10 weeks from submitting the online application to receiving their new Biometric Residence Permit, during which time they must not travel outside of the UK.
Applicants who have urgent travel plans will need to consider the super priority service available. Information about this can be found on the Skilled Worker Cost pages.
Once the Staff Immigration Team (SIT) have approved a Certificate of Sponsorship extension application, they issue and email the CoS to the applicant together with the in-country permission to stay application guidance.
The application process, for applicants and each dependant (if applicable), is undertaken in the following stages:
1. Completing and submitting an online application
This is based on the information provided in the Certificate of Sponsorship and is similar to the initial visa application. The system is intuitive and only asks for information relevant to the application being made. SIT is happy to provide guidance, and encourages applicants to email the final draft of their application to be checked before submission. An application cannot be amended once the ‘declaration’ section has been completed; therefore, the draft should be downloaded once the ‘document’ section has been reached.
Once the visa application fees, biometric enrolment, and Immigration Health Surcharge have been paid, two .pdf documents are generated: a summary of the application and a supporting evidence checklist.
SIT does not guarantee the successful outcome of any visa application; however, checking it helps to flag any inaccuracies or potential problems.
2. Submission of supporting documents
Applicants will be directed to upload scanned copies of the supporting evidence and book an appointment to register their biometric details (fingerprints and photographs) at a Sopra Steria UKVCAS centre.
There are UK Visa and Citizenship Application Service (UKVCAS) Centres around the UK:
7 Core Service Points which offer free appointments (Belfast, Cardiff, Croydon, Glasgow, Liverpool, Sheffield and Solihull);
50+ Enhanced Service Points, which charge an additional fee; and
1 Premium Lounge Service Point (London). A full table of costs including additional fees can be found on the Skilled Worker costs page.
The supporting evidence checklist provides the list of documents to scan and upload. This is done under the ‘Document upload’ section prior to the biometric enrolment appointment. Alternatively, the original documents can be taken to the appointment for uploading and scanning. Those applying at a Core Centre, as detailed at Step 3, will be charged additional costs for using the scanning service.
If any applicant requires assistance with scanning and uploading documents ahead of their appointment, or has any queries around which documents need to be submitted, they should seek support from SIT.
3. Enrolment of biometric details
Applicants must attend the appointment at their selected UKVCAS centre and provide their biometric details before a decision is made on their application. Children under the age of 16 must be accompanied by the responsible adult named in the child's application.
Applicants will be told what they need to take to the appointment at the time of booking. These are typically:
Passport or travel document;
Supporting documents as stated on the document checklist (even if these have already been scanned and uploaded, it is advisable to bring the original documents along in case they need to be reviewed or re-scanned).
The Home Office will issue a decision letter via Royal Mail, and the new Biometric Residence Permit (BRP) for the applicant and each dependant are delivered by courier within 10 working days after the decision.
Holders of certain visas may be able to switch into different visa categories whilst remaining in the UK, as long as they submit their application before their existing visa expires. For tailored advice on whether this is possible and what procedures to follow, please contact the Staff Immigration Team.
The University of Oxford has a responsibility to monitor any changes to visa holders' circumstances and report these changes to the Home Office where required. This includes changes to the visa holder's job title, main duties, salary, work location, etc.
End of sponsorship - Skilled Worker
When a visa holder's employment comes to an end and a visa extension will not be pursued, the department or college is required to inform the Staff Immigration Team (SIT) about this within five days after the employment has ceased.
SIT will report end of sponsorship to the Home Office who in turn may curtail the existing visa.
If the visa holder has secured employment with a different sponsor, they will be required to make a new (change of employment) Skilled Worker application with a Certificate of Sponsorship issued by their new employer.
If no other employment is envisaged, they will be required to leave the UK either upon expiration of their visa, or by the time limit provided by the Home Office in their letter of curtailment. In cases where employment has ended early, individuals typically are granted up to 60 days until the curtailment takes effect.
End of sponsorship - Tier 5
Once a sponsored researcher completes their engagement with the University, the department or college will inform SIT, who will then report end of sponsorship to the Home Office. If this happens earlier than the visa expiry date, the Home Office will write to the visa holder to confirm details of their curtailment.
If a sponsored visa holder leaves early or switches to a different visa, the sponsor must report the end of their sponsorship to the Home Office who then curtail (cancel) their visa.
When reporting the end of sponsorship, the sponsor must provide the visa holder's last known UK contact details (address, telephone number, and email address). When the Home Office cancels the visa, they will send a letter by email or post to the addresses provided for the visa holder. This 'curtailment letter' will explain that they have 60 days to either leave the UK or apply for a different visa.
If the visa holder has already applied for a new visa, a curtailment letter should not be issued by the Home Office; however, occasionally they can be issued in error. If a curtailment appears to have been issued in error, advice should be sought from the Staff Immigration Team (SIT).