Assigning Certificates of Sponsorship Defined Versus Undefined and Common Errors: Clear Guidance for Employers

You need to know when to use defined or undefined Certificates of Sponsorship and how to assign them correctly to avoid costly mistakes. Use defined CoS for people applying from abroad under your yearly allocation, and undefined CoS for workers switching to you from within the UK or other eligible routes.

This article shows how to manage assignments, spot common errors, and stay compliant with Home Office rules so your hiring stays smooth and lawful. Follow practical steps and clear examples to protect your licence and keep skilled staff working without delays.

What Is a Certificate of Sponsorship?

A Certificate of Sponsorship (CoS) is an electronic record that links a named job and worker to your sponsor licence. It proves you have offered a specific role to a person from outside the UK and that the role meets the rules for a Skilled Worker visa.

Role and Purpose in the UK Immigration Process

A CoS is not a paper document. You assign it in the Sponsor Management System (SMS) to give a migrant the reference they need for a visa application. The CoS includes job details: job title, SOC code, salary, start date and whether the role is temporary or permanent.

These details let UKVI check if the job meets skill and pay thresholds for the Skilled Worker route. The migrant uses the CoS reference number when they apply for leave to enter or remain. If the information on the CoS is wrong, the visa can be refused or later revoked, so accuracy matters.

Sponsor Licence and Eligible Employers

Only organisations with a valid sponsor licence can assign a CoS. You must hold the right licence type (typically Skilled Worker) and be listed on the licence for the relevant branch or site. UKVI assesses your HR systems, record‑keeping and ability to meet duties before granting a licence.

Small employers often need an annual allocation of undefined CoS, while larger or repeat sponsors may request defined CoS for specific roles. You must check an applicant’s right to work and criminal record requirements before assigning a CoS to stay compliant.

Sponsor Management System and Responsibilities

You use the SMS to request, create and assign both Defined and Undefined CoS. The SMS records every CoS you issue and the key obligations you must meet: reporting absences, changes in employment, and non‑attendance. Named authorising officers, key contacts and level managers handle assignments and must keep logs and evidence.

You must keep copies of documents used to recruit and check right to work for at least one year after the worker leaves. Breaching these SMS duties can lead to downgrade or loss of your sponsor licence and affect your ability to issue future CoS.

Defined Versus Undefined Certificates of Sponsorship

You need to know when to request a defined CoS and when an undefined CoS will work. The choice affects processing time, evidence you must supply, and how you use your annual CoS allocation.

Defined Certificates of Sponsorship: Criteria and Use Cases

A defined certificate of sponsorship (defined CoS / DCOS) is for people applying from outside the UK for a Skilled Worker visa or certain Global Business Mobility routes that require entry clearance. You request a defined CoS from the Home Office and must show why the job can’t be filled by a settled worker. Typical uses include senior hires overseas or roles that trigger additional checks, such as shortage occupations or higher-skilled roles.

You must demonstrate precise job details: job title, SOC code, salary, start date and that the role meets the Skilled Worker route criteria. Processing is typically slower than assigning an undefined CoS because the Home Office vets the case before issuing the CoS.

Use a defined CoS when your migrant is outside the UK and needs entry clearance, when you have exceeded your undefined allocation, or when the route specifically requires it.

Undefined Certificates of Sponsorship: Criteria and Use Cases

An undefined certificate of sponsorship (undefined CoS / UCOS) is assigned directly by you from your employer allocation for people already in the UK or switching into the Skilled Worker route. You don’t request it from the Home Office first.

Undefined CoS is suitable for internal transfers under Global Business Mobility, employees applying for permission from within the UK, or hires where you have spare CoS allocation. You must still record full job details in the sponsorship management system and ensure the job meets eligibility rules.

Keep careful records of your CoS allocation and assignment. Running out of undefined CoS or needing entry clearance for a candidate means you must move to a defined CoS instead.

Key Differences Between Defined and Undefined CoS

• Request process: Defined CoS must be requested from the Home Office; undefined CoS is assigned from your allocation.

• Where the applicant is: Defined usually for applicants outside the UK needing entry clearance; undefined for applicants inside the UK or switching routes.

• Timing and evidence: Defined involves Home Office vetting before issue; undefined is quicker but requires accurate internal assignment and reporting.

• Allocation impact: Undefined CoS uses your annual or monthly allocation; defined CoS counts against allocation only when issued by the Home Office.

• Route specifics: Some Global Business Mobility routes and Skilled Worker entry clearance cases require a defined CoS by rule.

Keep these points in mind to avoid errors when assigning DCOS or UCOS and to manage your CoS allocation accurately.

Assignment Process and Management

You must follow strict steps to request and assign a CoS, track your annual allocation, and keep records in the Sponsor Management System (SMS). The most important actions are requesting the right type of CoS, entering the correct SOC 2020 occupation code and salary, and keeping clear records of each CoS reference number and start date.

Requesting and Assigning a Certificate of Sponsorship

You request an undefined CoS from the Home Office when you need flexibility; you request a defined CoS for a named individual outside your allocation. Use the SMS to create the CoS record, enter the correct SOC code (SOC 2020 occupation code) and the precise job start date, then assign the CoS to the worker so the system issues a unique CoS reference number.

Make sure the person who approves the CoS in your organisation is an Authorising Officer or a named role with permission in the SMS. Double-check the occupation code, job title and salary against your vacancy and the Skilled Worker rules before you assign a CoS to avoid refusals or compliance action.

Common practical checks:

• Confirm the CoS start date matches the contract and visa application window.

• Verify the salary meets the minimum or the going rate for the SOC code.

• Save the CoS reference number and assignment record in your files.

Annual CoS Allocation and In-Year Requests

You get an annual allocation of undefined CoS based on your sponsor licence and past use. Monitor your remaining allocation in the SMS to avoid unexpectedly running out. If you need more undefined CoS during the year, submit an annual allocation request or an in-year request to the Home Office with clear reasons and planned start dates.

When making a request, include projected recruitment dates and the number of CoS needed. Timely requests reduce delays in hiring. If you expect high demand for defined CoS (for specific individuals), plan budgets and document why those roles cannot use undefined CoS to support any allocation review.

Keep a simple log showing: type of CoS (defined/undefined), date requested, CoS start date, and CoS reference number. This helps when you reconcile use against your annual allocation.

Managing Sponsor Duties and Record-Keeping

You must keep accurate records for every CoS assignment and be ready to show them in an audit. Record items for each worker include: assigned CoS reference number, SOC code used, assignment date in the SMS, contract start date and proof of right to work checks. Keep digital copies in a secure folder and link them to the SMS entry.

Assign clear staff responsibilities: who assigns CoS in the SMS, who checks SOC codes and salaries, and who files the evidence. Regularly review your SMS entries to catch errors such as wrong SOC code, incorrect salary or mismatched start date. Small mistakes can lead to visa refusals or compliance action, so log corrections and the reason for any change.

Common Errors and Compliance Risks

You must assign the right type of CoS, pay the correct salary, and keep accurate records. Mistakes on these points often trigger visa refusals, fines, or a compliance audit that can threaten your sponsor licence.

Incorrect Use of Defined or Undefined CoS

Assigning a Defined CoS (DCoS) when you should use an Undefined CoS, or vice versa, is a common error. Use a DCoS only for overseas workers applying from outside the UK under a Skilled Worker route and when you have a DCoS allocated to you. Use an Undefined CoS for in-country switches, extensions, or when the worker is already in the UK and meets the route rules.

If you use the wrong type, the Home Office will usually refuse the visa and keep the CoS allocation. That waste costs you the CoS assignment fee and may exhaust your DCoS quota. Repeated mistakes flag your account for compliance checks and raise the risk of licence suspension.

Salary, SOC Code and Occupation Code Mistakes

You must enter the correct salary, SOC code and occupation code on the CoS. The salary must meet the minimum salary or the going rate for the role, whichever is higher, and comply with the immigration salary list and any route-specific thresholds. Remember to include benefits correctly and apply the immigration skills charge where required.

Using the wrong SOC or occupation code misrepresents the job and can lead to visa refusals. Underpaying against the going rate or minimum salary triggers refusals and can prompt a compliance audit. Keep evidence of how you calculated pay, the job description, and market data to show salary compliance if asked.

Record-Keeping Failures and Reporting Issues

You must keep accurate records for every sponsored worker. Retain right-to-work checks, copies of passports, contact details, and proof of work location and salary for the required retention period. Update your sponsor management system (SMS) promptly when a worker does not start, stops work, or there is a significant change in role or salary.

Failing to report absences, terminations, or material changes within the Home Office deadlines is a serious breach. Missing records or late reporting make you vulnerable to compliance audits and fines. Maintain a checklist, set reminders, and log all CoS assignment decisions and communications to show full compliance.

Consequences: Visa Refusals, Licence Suspension and Audits

Visa refusals are the immediate consequence of many CoS errors. The Home Office will usually refuse applications with incorrect CoS type, wrong salary, or incorrect SOC code. Each refusal wastes the CoS fee and the applicant’s visa fee and can affect your recruitment plans.

Widespread or repeated breaches may lead to a compliance audit. Audits examine your systems, payroll, records and reporting. Serious findings can trigger licence suspension or revocation, civil penalties, or requirements to repay immigration skills charge errors. You must prepare evidence and correct faults quickly to reduce the risk of long-term sanctions.

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