Insurance & legal
Public liability £5m minimum. Property insurance with cover for guest stays (not just standard landlord). Gas Safe certificate where applicable. Electrical certificate.
Safeguarding
If you're sending mixed-team crews including under-18s or vulnerable adults, the accommodation supplier needs DBS-checked staff for any guest-facing work. Verify before approval.
Data protection
Booking data contains personal information. The supplier needs a GDPR-compliant data processing agreement. Standard practice for most established suppliers; ask if unclear.