Certificate of Sponsorship UK: A Plain-English Guide for Employers and Workers

Your employer's HR team just told you they've "never done visa sponsorship before." That's the moment most skilled workers panic — or quietly drop their job search. But the UK's certificate of sponsorship system is not as complex or expensive as it sounds, and many small employers who initially resist sponsorship come around once they understand what they're actually signing up for. Here is a clear breakdown of the process, the costs, and how to have the conversation that gets you from "we don't do sponsorship" to a signed job offer.

What a Certificate of Sponsorship Is

A Certificate of Sponsorship (CoS) is not a paper certificate. It is a unique reference number — a 12-character alphanumeric code — that a licensed employer assigns to a specific worker for a specific role. You enter that number in your Skilled Worker visa application as evidence that a UK employer is backing you.

The CoS links you to your employer, your job title, your salary, and your SOC 2020 occupation code. All of those have to match the details you submit when applying for your visa, so precision matters. The Home Office cross-checks them.

There are two types:

Defined CoS — used for workers applying from outside the UK. Employers request these in batches from their sponsor management system.

Undefined CoS — used for in-country switches, such as a Ukrainian on a Homes for Ukraine (HfU) visa switching to a Skilled Worker visa without leaving the UK.

Step 1: The Employer Gets a Sponsor Licence

Before any CoS can be issued, the employer must hold a valid sponsor licence from the Home Office. Companies that have never sponsored a worker before need to apply first.

The application fee is:

• £611 for small or charitable sponsors (under 50 staff, or annual turnover under £10.2 million)
• £1,682 for medium and large sponsors

"Small" vs "large" is assessed at the time of application based on Companies House data. Most SMEs — the category of employer most likely to be new to sponsorship — pay £611.

Processing takes around eight weeks for a standard application. There is a priority service for an additional £500 that targets a ten-working-day turnaround, though this is not guaranteed.

The licence, once granted, is valid indefinitely — it does not expire on a fixed term. The employer must maintain compliance (reporting worker absences, salary changes, or role changes through the Sponsor Management System) but does not need to renew it annually.

Step 2: The CoS Is Assigned

Once licensed, the employer logs into the Sponsor Management System and assigns a CoS to the worker. The fee for each CoS is £525, paid by the employer.

This is a one-time fee per worker, not per year. It covers the assignment of the CoS, not the worker's visa application itself. The visa fees are paid separately by the worker.

The CoS is valid for three months — the worker must submit their visa application within that window.

Step 3: The Immigration Skills Charge

Here is where costs add up for employers. The Immigration Skills Charge (ISC) is an annual levy paid by sponsors on top of everything else. It is designed to fund domestic skills training.

Rates in 2026:

• £480 per year for small/charitable sponsors
• £1,000 per year for medium sponsors
• £1,320 per year for large sponsors

For a three-year visa, a small employer pays £1,440 in ISC. A large employer pays £3,960.

Some roles are exempt from the ISC — PhD-level sponsored workers are exempt, as are some science, technology, and research roles. Check GOV.UK's ISC exemptions page before assuming the charge applies.

The Full Cost Picture for a Small Employer Sponsoring One Worker

If an employer is starting from scratch — no existing licence, sponsoring their first worker on a three-year Skilled Worker visa — the combined upfront and ongoing government costs look like this:

This does not include any legal fees an employer might pay to an immigration solicitor to prepare the licence application. Solicitor fees for a licence application typically run £1,000–£2,500 for a straightforward case.

Spread over three years, the government cost alone is roughly £860 per year — less than the cost of recruiting through a specialist agency.

How to Convince an Employer to Sponsor Your Visa

The most common reason employers say no is not the cost — it is unfamiliarity and perceived administrative burden. They imagine a mountain of paperwork and ongoing Home Office scrutiny.

The reality is that running a sponsor licence on an ongoing basis requires the employer to:

1. Report significant changes in the worker's circumstances (such as a role change or unexplained absence of ten or more working days) through the Sponsor Management System
2. Keep employment records, right-to-work checks, and salary records in a form that can be audited
3. Notify the Home Office if the worker stops working for them

These are not onerous for a business that already keeps standard HR records. Many sponsors go years without any contact from the Home Office compliance team.

When you approach an employer, frame sponsorship as a retention tool rather than a concession. Workers who have been sponsored are significantly more loyal — they are tied to the employer for the visa duration and cannot easily walk to a competitor without starting the sponsorship process over. For specialist technical, engineering, or healthcare roles where recruitment is difficult, that stickiness has real value.

Come to the conversation with a one-page cost summary (use the figures above), the GOV.UK guidance link, and an offer to connect them with a recommended immigration solicitor if they want professional guidance before deciding.

What Workers Pay

The CoS is the employer's responsibility. The worker pays the visa application fee directly to the Home Office:

• £827 for a Skilled Worker visa up to three years (from outside UK)
• £1,636 for a Skilled Worker visa over three years

Workers applying from inside the UK (switching from a Ukraine scheme) pay the same rate. The fee is non-refundable even if the application is refused, so submitting a complete and accurate application matters.

Workers must also pay the Immigration Health Surcharge at £1,035 per year (£776 per year for children under 18). For a three-year visa, that is £3,105 per adult. There is no exemption for Ukrainians switching from a humanitarian visa — the IHS exemption that applied to the original Ukraine scheme does not carry over to a Skilled Worker visa.

The Occupation Code Matters as Much as the Salary

When an employer assigns a CoS, they must classify the role using a SOC 2020 code. This code determines the "going rate" — the Home Office's minimum salary for that specific occupation. Your offered salary must be at least the higher of the general threshold (£41,700 in 2026 for standard applicants) or 100% of the going rate for your SOC code.

Getting the SOC code wrong is one of the most common reasons employer-sponsored applications are refused or delayed. A software developer coded under the wrong engineering category can trigger a going rate that the salary doesn't meet. Make sure both you and your employer review the Appendix Skilled Occupations on GOV.UK before the CoS is assigned.

Switching Within the UK from a Ukraine Scheme

If you're already in the UK on a Homes for Ukraine or Ukraine Permission Extension visa, you can switch to a Skilled Worker visa without leaving the country. The process is the same — your employer assigns you an undefined CoS, you pay the visa fee, and you submit a switch application online.

The main advantage: your five-year ILR clock starts from the date the Skilled Worker visa is granted. Time spent on the Ukraine schemes does not count toward settlement. So the sooner you switch, the sooner you begin building toward indefinite leave to remain.

For a step-by-step walkthrough of the full transition from humanitarian leave to Skilled Worker status — including salary thresholds, SOC code selection, and the ILR timeline — the Ukraine to UK Visa Pathway Guide covers the end-to-end process in plain language.