1. What is the Certificate of Sponsorship (CoS)?
A Certificate of Sponsorship (CoS) is an electronic record — not a paper certificate — issued by a Home Office–approved employer in the UK. It authorises a foreign national to apply for a Skilled Worker Visa or other UK work visas.
Each CoS includes a unique reference number confirming that:
- The UK employer is licensed to sponsor overseas workers.
- The offered job meets the Home Office’s skill level and salary requirements.
- The role complies with immigration and sponsorship regulations.
There are two main types of CoS:
Defined CoS
- Used for Skilled Worker Visa applicants applying from outside the UK.
- Must be requested individually via the Sponsor Management System (SMS).
Undefined CoS
- Used for applicants already in the UK (e.g., switching visas or extending an existing Skilled Worker Visa).
- Allocated annually to licensed sponsors for internal use.
Understanding which type you need is essential for accurate and timely visa processing.
2. Typical Processing Time for a Certificate of Sponsorship
The processing time for a CoS depends on the type and whether the employer already holds an active sponsor licence.
| Type of CoS | Average Processing Time (2024) | Notes |
|---|---|---|
| Defined CoS | 1 business day | After submission via SMS; may take longer if the Home Office requests further information. |
| Undefined CoS | Immediate (if allocation available) | If the employer runs out of allocations, requesting more may take up to 18 weeks. |
If the sponsoring employer already has a valid sponsor licence and unused CoS allocations, issuing the certificate is usually instantaneous.
3. Steps in the CoS Request Process
Employers must complete several key steps before issuing a CoS:
Step 1: Apply for a Sponsor Licence (if not already held)
- Employers without a Home Office sponsor licence must apply first.
- Processing time: approximately 8 weeks.
- A priority licence service (available for £500) can reduce this to 10 working days if accepted.
Step 2: Request a Defined CoS (for overseas workers)
- Employers request each CoS through the Sponsor Management System (SMS).
- The Home Office usually processes this within 1 business day.
Step 3: Assign the CoS
- Once approved, the employer assigns the CoS to the worker via the SMS.
- The employee receives a unique CoS reference number, required for their visa application.
If the sponsor has undefined CoS allocations available, they can assign one immediately without waiting for Home Office approval.
4. Fast-Tracking the CoS Application
Although there is no formal premium service for CoS issuance, employers can significantly reduce processing delays by following best practices:
- Ensure compliance before applying:
Verify that the company’s sponsor licence, HR systems, and job offer meet Home Office standards. - Plan allocations in advance:
Request sufficient undefined CoS allocations at the start of each year to avoid waiting up to 18 weeks for extra CoS approvals. - Avoid administrative errors:
Inputting incorrect job titles, SOC codes, or salary figures in the SMS can trigger Home Office reviews and delay processing. - Maintain good compliance history:
Sponsors with a clean record and accurate reporting history typically experience faster approvals.
Being proactive and compliant can help employers avoid the most common CoS delays.
5. CoS Validity and Visa Application
Once issued, a Certificate of Sponsorship is valid for 3 months.
The sponsored worker must use it within this time to apply for their UK visa.
Key points:
- A CoS cannot be reused once issued.
- The visa application must match the details on the CoS (employer name, job title, SOC code, and salary).
- If the CoS expires before use, the employer must assign a new one.
Once the visa is granted, the CoS becomes “used” in the Home Office system.
6. Frequently Asked Questions (FAQs)
Q1: How long does it take to issue a defined CoS?
A defined CoS is typically approved within 1 business day of submission through the SMS.
Q2: Can a CoS be fast-tracked?
There is no official premium processing for CoS, but employers can expedite the process by ensuring full compliance and planning allocation requests early.
Q3: What if my CoS request is delayed?
Delays usually occur when the Home Office requests further information or if the sponsor’s licence is under review. Employers can contact the Sponsor Management System (SMS) support team for updates.
Q4: Can I apply for a Skilled Worker Visa without a CoS?
No. The CoS reference number is a mandatory part of your visa application.
Q5: How long is a CoS valid once issued?
A CoS is valid for 3 months and must be used within that timeframe.
Q6: Do I need a new CoS if I change employers?
Yes. Each new job or employer requires a new Certificate of Sponsorship issued by the new sponsor.
7. Summary
| CoS Type | Who It’s For | Processing Time | Validity |
|---|---|---|---|
| Defined CoS | Overseas applicants (new hires) | 1 business day | 3 months |
| Undefined CoS | Applicants already in the UK | Immediate if allocation available; up to 18 weeks if new allocation needed | 3 months |
Timely CoS processing depends largely on the employer’s sponsor licence readiness, compliance record, and planning for allocations.
Conclusion
The UK Certificate of Sponsorship (CoS) is an essential part of the Skilled Worker Visa process, linking a sponsored worker to their approved UK employer. While defined CoS approvals are typically processed within one business day, undefined CoS allocation requests may take longer — up to 18 weeks if not pre-planned.
Employers who maintain compliance and plan allocations in advance can ensure a faster, smoother onboarding process for international employees.
For fixed-fee immigration assistance with UK sponsorship licences or Skilled Worker Visa applications,
contact Martin Taggart — your trusted UK immigration partner.