Defined and Undefined Certificates of Sponsorship: UK Sponsor Choice

For a Skilled Worker application, choose a Defined CoS for entry clearance from outside the UK, or an Undefined CoS for an eligible application for permission to stay within the UK. [3][5][6] Base the choice on the application the worker will make—not simply their nationality or present location. [3][5][6]

A Certificate of Sponsorship (CoS) is an electronic record with a unique reference number used in the worker’s visa application. [3][5]

Identify the worker’s application circumstances

These hypothetical cases show the distinction:

• Overseas candidate applying for Skilled Worker entry clearance: choose a Defined CoS. [3][5]
• Student or Graduate eligible to switch to Skilled Worker within the UK: choose an Undefined CoS. [3][5]
• Existing Skilled Worker eligible to apply in-country to extend permission or change employer: choose an Undefined CoS. [3][5]

Confirm switching eligibility before selecting the in-country option; being physically in the UK does not establish it. [1] Undefined CoS also serve other sponsored routes, including overseas applications, so this overseas-versus-in-country distinction is specific to Skilled Worker applications. [3][5][6]

Keep licence, certificate and visa decisions separate

First check whether sponsorship is needed. Irish citizens, people with EU Settlement Scheme status and people with indefinite leave normally do not need it; this is not an exhaustive list. [1]

The employer must hold a valid sponsor licence covering Skilled Worker. An existing licence without that route needs the route added. [1] The licence authorises sponsorship; the CoS records sponsorship of the individual worker and role. Assigning a CoS does not guarantee visa approval: the worker must separately meet the requirements for entry clearance or permission to stay. [1][6]

Check eligibility and the role before assignment

Check the worker’s immigration category, permission history and intended application. Previous Skilled Worker sponsorship can affect transitional occupation or salary treatment, so record the relevant dates rather than assuming the same rules apply to every worker. [1][4]

Before assignment, the sponsor must be satisfied the worker can meet the route requirements and the job is genuine, eligible, appropriately skilled and meets the applicable salary rules. [1] Match the actual duties—not merely the job title—to the four-digit SOC 2020 occupation code. Migrate UK recommends the code describing the majority of the role where duties overlap. [4]

Check English-language, finance, genuine-intention and, where relevant, criminal-record, switching and entry requirements. This is not an exhaustive eligibility checklist. [1]

The role must comply with minimum-wage and working-time rules. Sponsors must not assign a CoS to hire someone out to fill a third party’s position or provide an ongoing routine role or service for that third party. [1]

Request approval or check your allocation in SMS

Confirm eligible Key Personnel and authorised Sponsorship Management System (SMS) users are in place to request and assign certificates. [1][6]

• Defined CoS: request the individual certificate through SMS. UKVI assesses the request and, if approved, makes it available in the sponsor’s account for assignment. Approval and assignment are separate steps. [3][5] Once a Defined CoS is allocated, it must be assigned within 90 days or it is removed from the account. [1]
• Undefined CoS: check the remaining approved allocation and assign from it. If the allocation is insufficient, request additional allocation through SMS rather than substituting a Defined CoS. [3][5]

Before assignment, check personal, contact and passport details; job title and duties; occupation code; salary and weekly hours; work location; and employment start and end dates. Pay the applicable CoS fee and any Immigration Skills Charge, then give the worker the reference number. [3][6]

Sponsors must retain supporting records for each sponsored worker, including recruitment information. [1]

Resolve uncertain cases and check timing

Seek advice before assignment if switching eligibility or immigration history is unclear, previous sponsorship may trigger transitional treatment, mixed duties make the occupation code uncertain, or the role involves third-party working whose permissibility is unclear. [1][4]

The pre-populated details on an allocated Defined CoS cannot be edited when you assign it. Home Office guidance allows a sponsor note only for a change to the salary or weekly hours (provided the salary remains eligible for the same number of points) or to the job start and end dates. A change to the occupation code or job description cannot be made by sponsor note: you must tell UKVI so it can cancel the CoS. [1] Obtain case-specific advice before changing a record in circumstances the guidance does not address.

Plan for the worker to apply within three months of assignment and no earlier than three months before the CoS start date. [3][5] Before acting, check the guidance version and date on GOV.UK: UKVI warns its guidance is subject to change. [1][2]