Hiring a skilled worker from overseas can bring valuable talent into your business – but it also involves a strict set of legal steps. One of the most important requirements is issuing a Certificate of Sponsorship (CoS). Without one, your prospective employee cannot apply for a Skilled Worker Visa or other work-based immigration routes.
In this guide, we explain what a Certificate of Sponsorship is, who can issue one and how to apply for and assign it correctly. Whether you’re a first-time sponsor or expanding your international recruitment, it’s essential to get this step right.
What is a Certificate of Sponsorship?
A Certificate of Sponsorship is a digital record issued by a licensed UK employer that confirms a job offer has been made to a non-UK national. Despite its name, there’s no physical certificate – instead, the sponsor assigns a reference number via the Home Office’s online system.
This reference number is used by the applicant when submitting their visa application. The certificate contains key details such as the job title, salary, start date, working hours and confirmation that the role meets UK immigration requirements.
Different types of Certificates of Sponsorship
There are two types of Certificates of Sponsorship used in the Skilled Worker visa route:
- Defined CoS: Used for workers applying for a visa from outside the UK. Sponsors must request these individually from the Home Office and approval is usually granted within one working day unless further checks are needed.
- Undefined CoS: Used for workers already inside the UK (for example, those switching visa categories or extending their stay). Sponsors can apply for an annual allocation of these to use as needed.
Choosing the right type is critical. Using the wrong category could lead to visa delays or refusals, which can have serious consequences for both employer and applicant.
Who can issue a Certificate of Sponsorship?
Only employers with a valid sponsor licence are allowed to issue Certificates of Sponsorship. To obtain a licence, your organisation must apply to the Home Office and meet a range of requirements – including proving that your business is genuine, operating lawfully and able to meet ongoing sponsor duties.
Employers must also be able to demonstrate that any job they are sponsoring meets the required skill level and minimum salary thresholds for the visa route.
How to apply for a Certificate of Sponsorship
Once you hold a sponsor licence, the process of assigning a Certificate of Sponsorship depends on the type required. For undefined CoS, you’ll receive an annual allocation that can be assigned to eligible candidates using the Sponsorship Management System (SMS).
For defined CoS – usually needed for overseas workers – you must submit a request via the SMS. The Home Office will assess the role, salary and details provided before granting approval. Once approved, you can assign the certificate to the specific individual.
Each Certificate of Sponsorship must include accurate information about the job, including:
- Job title and Standard Occupational Classification (SOC) code
- Salary and working hours
- Start and end dates
- Confirmation of how the role meets visa criteria
Accuracy is critical. Mistakes or missing information can result in the visa being refused or the certificate being invalidated. Many businesses choose to work with immigration solicitors to ensure everything is completed correctly the first time.
What happens after the certificate is issued?
Once assigned, the Certificate of Sponsorship reference number is sent to the worker. They will use this as part of their Skilled Worker visa application, alongside other documents such as their passport, proof of English language ability and financial information (if applicable).
The certificate is valid for three months from the date it’s issued. If the individual doesn’t apply within that time, a new certificate will need to be assigned.
After the visa is granted and the employee begins working, the employer must continue to meet all sponsor duties. This includes tracking the worker’s attendance, keeping up-to-date records and reporting changes in employment or contact details via the SMS.
What about self-sponsorship and start-ups?
Some entrepreneurs explore the option of self-sponsorship – where an individual sets up a UK business, applies for a sponsor licence and then sponsors themselves as a Skilled Worker. This is a complex route that requires meeting all standard sponsorship and business requirements and proving the company is legitimate, active and capable of hiring a genuine employee.
Legal advice is highly recommended for anyone considering self-sponsorship to avoid visa refusals or compliance issues later on.
Need help applying for a Certificate of Sponsorship?
At Osbourne Pinner Solicitors, our team of immigration solicitors helps businesses and individuals navigate the sponsorship process. Whether you’re applying for your first sponsor licence or assigning a Certificate of Sponsorship, we can guide you through every stage.
We offer a free 30-minute consultation to assess your case and provide tailored advice. Contact us today using the form below, call 0203 983 508 or email [email protected] to speak with one of our expert immigration solicitors.
You can come to our offices in Harrow, Canary Wharf, Piccadilly Circus or Manchester – or speak to us on a video call if you’d prefer a remote consultation.
