Table Of Contents:
- What is a Certificate of sponsorship (Cos)
- Certificate of sponsorship (CoS) UK – What is it
- Visas that require CoS
- Types of CoS
- CoS for sponsoring a UK Expansion Worker
- Cost of CoS
- Obtaining a Certificate of Sponsorship (CoS)
- Role of Certificate of Sponsorship (CoS)
- CoS does not guarantee the Visa
- CoS are not Transferrable
- Summary

Any UK business or organization looking to recruit foreign workers must assign a certificate of sponsorship (CoS) to the sponsoring workers under the UK work visa category. Assigning CoS is required to confirm that the applicant has met the relevant visa conditions. A Certificate of sponsorship (CoS) is an electronic record that includes details like the job title, salary offered, job location, start and end dates, and a unique reference number. Sponsor must give this reference number to the overseas workers whom they wish to employ because migrant workers need to enter this number as part of their application for entry clearance or leave to remain in the UK.
A CoS under the Skilled Worker route can be of 2 types – ‘Defined CoS’ and ‘Undefined CoS’.
What is a Certificate of sponsorship (Cos)?
In order to be able to assign CoS, an employer must have a sponsor licence from the Home Office.
A certificate of sponsorship CoS) is a mandatory electronic record each UK employer must assign to overseas workers they wish to recruit (sponsor) to work for their company or organization in the UK. Unless an overseas worker is assigned a CoS from their employer, they cannot apply for UK work visas.
When an employer assigns the CoS to an applicant, the applicant must use it to apply for their visa within 3 months of CoS being issued. A CoS contains details like the job title, salary offered, job location, start and end dates, details of the employee, and a unique reference number. The applicant must not apply for their visa for entry clearance or leave to remain more than 3 months before the start date of their job listed on the certificate of sponsorship.
Certificate of sponsorship (CoS) UK – What is it?
Foreign workers applying to work in the UK need a CoS. They will be assigned CoS from their UK employer. A licenced sponsor must also meet the strict conditions associated with their CoS. Any errors can result in the Home Office refusing a work visa application by the worker, and the Home Office can also enforce action against the employer, such as downgrading, suspending or even revoking their sponsor licence.
In this article, we are going to discuss some important points related to a Certificate of Sponsorship (CoS) UK.
1. Visas that require CoS
Foreign workers looking to apply for entry clearance or leave to remain under the following visa routes need a CoS from their UK employer.
- UK Skilled Worker Visa
- UK Global Business Mobility Visas, which include the following:
- Senior or Specialist Worker
- Graduate Trainee
- UK Expansion Worker
- UK Service Supplier
- UK Secondment Worker
- UK Scale-up Visas
- UK Minister of Religion Visa
- UK International Sportsperson Visa
- UK Creative Worker Visa
- UK Religious Worker Visa
- UK Government Authorised Exchange Scheme
- UK International Agreement
- UK Seasonal Worker Visa
2. Types of CoS
There are two types of certificates of sponsorship – Defined Certificates and Undefined Certificates.
Defined Certificates
Defined CoS are for people applying for entry clearance on a skilled worker visa from outside the UK. The sponsor must apply for defined certificates to employ these workers through the SMS (Sponsorship Management System). You’ll get access to the SMS only after getting your sponsor licence. After you have been approved for a defined certificate by the Home Office, you can then assign this to workers.
Undefined Certificates
Undefined certificates are for skilled workers applying for leave to remain from inside the UK, and applicants on all other visas. When an employer applies for their licence, the Home Office asks them to estimate how many undefined certificates they will need for workers and temporary workers in the first year.
3. CoS for sponsoring a UK Expansion Worker
If an employer’s licence has a provisional rating, they can only assign one certificate of sponsorship which they must assign to the authorising officer so that the officer can enter the UK. Once the authorising officer has obtained their visa, the employer can upgrade their licence to an A-rating and request up to 4 additional CoS using the SMS (Sponsor Management System).
4. Cost of CoS
Depending on the type of sponsor licence, the employer will need to pay a fee when they assign a CoS to a worker.
- Worker (except those on the International Sportsperson visa) – £525 per certificate
- Temporary Worker – £55 per certificate
- International Sportsperson – where the CoS is assigned for 12 months or less – £55 per certificate, and
- International Sportsperson – where the CoS is assigned for more than 12 months – £525 per certificate.
5. Obtaining a Certificate of Sponsorship (CoS)
If you are an employer looking to obtain a CoS, you need to follow the steps below:
- Submit the sponsor licence application to the Home Office with supporting documents and fee.
- Choose between ‘defined’ CoS and ‘undefined’ CoS and determine the number of CoS required based on your requirement.
- Request a Defined CoS through the Home Office or assign an Undefined CoS using the SMS (Sponsor Management System)
- After being assigned CoS, share the CoS reference number with the skilled worker for their UK work visas application.
- Keep your sponsor’s duty to monitor employees’ status and report any changes to the Home Office through SMS.
6. Role of Certificate of Sponsorship (CoS)
The role of CoS comes into play when a UK company or organisation wants to sponsor a skilled worker, or in other words, when a non-UK worker wants to apply for a UK work visa. Assigning a CoS to an individual means the sponsor is confirming to the Home Office that the employment conditions proposed by the employer are being complied with the relevant visa route requirements.
7. CoS does not guarantee the Visa
Even though a CoS enables employees to apply for work visas, it does not automatically guarantee that the Home Office will grant them the visa. They must still satisfy the other eligibility requirements for the visa. Also, the details on the CoS must match the information they have provided in their visa application.
8. CoS are not Transferrable
You should note that certificates of sponsorship (CoS) are not transferrable. If an employer reassigns a CoS to another individual, it would be considered a breach of the sponsor’s duties, leading to a potential enforcement action against the organization from the Home, such as downgrading, suspending, or even revoking their sponsor licence.
Summary
The Certificate of Sponsorship (CoS) is effectively a way for employers to self-certify that the job role they are recruiting skilled workers for meets the sponsorship requirements as set out in the visa conditions, such as the appropriate skill and salary threshold.
Employers also have to face several key risks when they assign a CoS. For example, incorrectly assigning a 4-digit SOC code, providing incorrect job information, or failing to meet the salary or skill level threshold can lead to an applicant’s work visa being refused.
Issuing the wrong type of certificate of sponsorship (CoS) can also lead to delays in application processing or application being rejected.
Read Other Blogs:
Difference Between Defined And Undefined COS