How far in advance should you book a safety inspection?

For most commercial safety inspections, booking 4-8 weeks in advance is the practical minimum. Inspectors in high-demand sectors (fire, electrical, LOLER) can have 6-8 week waiting lists, especially at busy periods (Q1 and Q3 tend to be busiest for building compliance). Food safety inspections by local authorities are unannounced and you can't book them -- but you can ensure the premises are always ready.

The booking lead time is the reason why setting a reminder at the expiry date itself is too late. A reminder at 90 days gives you time to book the inspector, prepare the relevant documentation, and address any minor issues before the inspection day. If a problem is found and re-inspection is required, 90 days gives breathing room. 30 days often doesn't.