Guide section
Defined vs undefined (high level)
Employers often discuss defined (typically for workers applying from outside the UK) and undefined CoS (often for in-country switches/extensions). Annual allocations and request processes differ — confirm the current SMS rules before you promise a start date.
| Topic | Why it matters to hiring |
|---|---|
| Allocation | You may need to request CoS before you can assign one |
| Accuracy | Job title, salary, SOC/occupation, and dates must match reality |
| Timing | Workers need the CoS reference to apply for the visa |
| Changes | Role changes after assignment can create compliance issues |
Guide section
Recruitment tip
Do not assign a CoS until the offer is firm and the role details are stable. Inaccurate CoS data creates visa risk and compliance exposure.
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Explore employer toolsCommon questions
Does assigning a CoS guarantee the visa?+
No. The worker must still meet the visa rules and be approved by UKVI.