The Home Office strongly recommends against booking travel to the UK before a visa is issued.
Skilled Worker visa holders must travel to the UK as soon as possible after the start date of their Skilled Worker vignette. Those issued a vignette valid for 90 days must travel to the UK within this period, as if they do not, they will have to apply, and pay, for a replacement vignette before entering the UK.
Travelling to the UK as a Visitor
Once an applicant has submitted their Skilled Worker visa application, or after their Skilled Worker visa has been granted, they must not enter the UK as a Visitor (e.g. as a tourist). If they do, their Skilled Worker visa will no longer be valid, and they will not be able to start their employment. Any travel plans should be discussed with the employing department/ faculty/ college and the Staff Immigration Team (SIT).
A Skilled Worker start date cannot be delayed more than 28 days (4 weeks)
If a Skilled Worker visa holder arrives more than 28 days late, unless there is some serious and unavoidable reason for the delay, their sponsorship would have to be withdrawn which would result in their Skilled Worker visa being cancelled. The 28 days are counted from either the Skilled Worker CoS start date or the date the Skilled Worker visa is issued, whichever is later.
If there are any concerns about meeting a Skilled Worker start date, please contact the Staff Immigration Team (SIT) as early as possible.