If you are searching for work in the United Kingdom from abroad, understanding the certificate of sponsorship UK process is one of the most important steps you will take. This document sits at the heart of the UK's points-based immigration system and is a legal requirement for most overseas workers hoping to secure a Skilled Worker visa. Whether you are a nurse, software engineer, chef, or engineer, this guide explains exactly what a certificate of sponsorship is, how to obtain one, what employers need to do, and what happens if something goes wrong.
What Is a Certificate of Sponsorship UK?
A certificate of sponsorship (CoS) is not a physical certificate or a paper document — it is a unique reference number assigned by a licenced UK employer and used to support a Skilled Worker visa application. The number is recorded on the UK Visas and Immigration (UKVI) system, and applicants use it when applying online at GOV.UK. Without this reference, your visa application cannot proceed.
It is worth understanding that the certificate of sponsorship UK framework exists to protect both the worker and the integrity of the immigration system. It confirms that a genuine job offer has been made, that the role meets the required skill level (typically RQF Level 3 or above), and that the salary meets the relevant threshold.
Types of Certificate of Sponsorship
There are two types of certificate of sponsorship that employers can assign, and the correct one depends on your situation:
- Defined CoS: Used for workers applying from outside the UK. Employers must apply to UKVI for a defined CoS before assigning it to the worker, and the number of defined certificates available to each sponsor is limited.
- Undefined CoS: Used for workers who are already in the UK and wish to switch, extend, or update their visa. Sponsors hold an annual allocation of undefined certificates and can assign them more quickly.
Knowing which type applies to your circumstances helps you ask the right questions during the recruitment process and avoids unnecessary delays.
Salary and Skill Requirements
From April 2024, the government raised the general salary threshold for Skilled Worker visas significantly. Workers must be offered a salary of at least £38,700 per year (or the going rate for the occupation, whichever is higher), unless the role falls under a shortage occupation or a specific exemption such as new entrants to the labour market. The GOV.UK website publishes the full list of eligible occupations and their associated Standard Occupational Classification (SOC) codes, which your employer must reference when assigning your certificate of sponsorship UK reference number.
How Employers Obtain a Sponsor Licence
Before any certificate of sponsorship UK can be issued, your prospective employer must hold a valid sponsor licence. This is granted by the Home Office and represents a significant commitment on the part of the organisation.
Applying for a Sponsor Licence
Employers apply for a sponsor licence through GOV.UK, submitting evidence that they are a legitimate, trading business with appropriate HR systems in place. The application fee ranges from £536 for small or charitable sponsors to £1,476 for medium or large sponsors. Once approved, the employer is added to the Register of Licensed Sponsors, which is publicly searchable — a step worth taking as a job seeker to verify your prospective employer's eligibility before accepting an offer.
The CIPD (Chartered Institute of Personnel and Development) advises HR professionals to maintain robust compliance records once a licence is granted, as the Home Office conducts spot checks and can revoke licences for non-compliance.
Sponsor Duties and Responsibilities
Licensed sponsors carry ongoing legal responsibilities. They must report certain changes to UKVI, including if a sponsored worker stops working for them or changes roles significantly. They must also keep records of workers' contact details and immigration status. ACAS guidance reminds employers that sponsored workers have the same rights as other employees under UK employment law, including rights around pay, working hours, and protection from discrimination.
If a sponsor's licence is revoked, workers assigned a certificate of sponsorship UK under that licence may face serious consequences, including having to find a new sponsor or leave the UK. It is therefore sensible to research your prospective employer thoroughly, looking at Companies House records and checking the register of licensed sponsors.
How to Apply for a Skilled Worker Visa Using Your Certificate of Sponsorship
Once your employer has assigned you a certificate of sponsorship UK reference number, you can begin your Skilled Worker visa application. The process is completed online through the GOV.UK portal, and you will need to gather a range of supporting documents.
Documents You Will Need
The core documents typically required include:
- Your certificate of sponsorship reference number
- A valid passport or travel document
- Proof of English language ability (unless exempt)
- Evidence of meeting the financial requirement (you must show you have at least £1,270 in savings, held for 28 consecutive days, unless your sponsor certifies maintenance)
- Tuberculosis (TB) test results if you are applying from a country where this is required
- Qualifications relevant to your role, where applicable
GOV.UK provides a full document checklist tailored to your specific situation, and it is advisable to use the official guidance rather than relying solely on third-party sources.
Fees, Processing Times, and Priority Services
The visa application fee for a Skilled Worker visa ranges from £719 to £1,639 depending on the length of the visa and whether it is applied for inside or outside the UK. You will also need to pay the Immigration Health Surcharge, which is currently set at £1,035 per year of your visa. Processing times vary, but standard applications from outside the UK are typically decided within three weeks. A priority service is available for an additional fee of £500, reducing the decision time to five working days in most cases.
Job boards such as Reed regularly feature roles with Skilled Worker visa sponsorship available, making it a practical first port of call when searching for eligible opportunities.
Certificate of Sponsorship UK: Common Problems and How to Avoid Them
Navigating the certificate of sponsorship process is not always straightforward, and understanding common pitfalls can save considerable time and money.
Delays in Assigning Your Certificate
One of the most frequent issues is a delay between accepting a job offer and receiving your certificate of sponsorship UK reference number. Defined CoS requests can take UKVI several weeks to process, particularly during busy periods. To minimise disruption, ask your employer early in the recruitment process whether they already hold an allocation of certificates and how long the assignment process typically takes within their organisation.
Incorrect Occupation Codes and Salary Errors
Another common problem arises when an employer assigns a certificate of sponsorship with the wrong SOC code or a salary below the applicable threshold. If UKVI identifies a discrepancy during your visa application, the application may be refused. Before your employer submits the CoS, it is good practice to review the listed occupation code and salary against the official GOV.UK tables together, ensuring everything aligns with the job duties you have been offered.
Withdrawing or Changing a Certificate of Sponsorship
If your circumstances change — for example, if you decide to withdraw from a role before starting or if the employer significantly changes the job — the CoS may need to be withdrawn and reissued. Sponsors can withdraw a CoS up until the point a visa has been granted. Once a visa is issued, changes to the role may require a new CoS and potentially a new visa application, so clear communication with your employer is essential throughout.
After You Arrive: Maintaining Your Sponsored Status
Receiving your Skilled Worker visa and arriving in the UK is a significant milestone, but your responsibilities do not end there. Maintaining your sponsored status requires ongoing attention from both you and your employer.
Switching Employers or Roles
If you wish to change employers while in the UK, your new employer must be a licenced sponsor and must assign you a new certificate of sponsorship UK reference number. You cannot simply start working for a new employer on the strength of your current visa. In most cases, you will need to make a new visa application before switching, although there are provisions for some workers to begin working for a new sponsor before the application is decided.
Extending Your Skilled Worker Visa
Skilled Worker visas are initially granted for up to five years. To extend, your employer must assign you a new certificate of sponsorship UK reference, confirming that you are still employed in an eligible role at the required salary. After five continuous years on a Skilled Worker visa, most workers become eligible to apply for Indefinite Leave to Remain (ILR), which removes the need for ongoing sponsorship altogether — a significant step towards building a long-term future in the UK.
Frequently Asked Questions
1. How long does it take to get a certificate of sponsorship UK?
The time varies depending on the type of CoS. For undefined CoS, employers can assign them immediately from their annual allocation. For defined CoS (used for overseas applicants), employers must apply to UKVI, which typically takes around eight weeks, though this can vary. Processing times are published periodically on GOV.UK.
2. Can I apply for a Skilled Worker visa without a certificate of sponsorship?
No. A certificate of sponsorship UK reference number is a mandatory requirement for a Skilled Worker visa application. You cannot proceed without one, regardless of your qualifications or experience.
3. How much does a certificate of sponsorship cost for the employer?
Employers pay a fee to assign each certificate of sponsorship. As of 2024, the fee is £239 for a defined CoS and £239 for an undefined CoS. These fees are in addition to the cost of obtaining and maintaining the sponsor licence itself.
4. What happens if my sponsor's licence is revoked?
If your employer's sponsor licence is revoked, you will typically be given a period (usually 60 days) to find a new licenced sponsor and make a new visa application. GOV.UK and ACAS both advise workers to seek immigration legal advice quickly if this situation arises.
5. Can my employer charge me for the certificate of sponsorship?
No. Employers are legally prohibited from passing the cost of a certificate of sponsorship UK to the worker. Doing so breaches sponsor licence conditions and could expose the employer to enforcement action by the Home Office.