We won our first Norwegian contract — what must exist before day one?

Registrations (entity + VAT if you'll cross NOK 50,000), employer registration and a-melding readiness if anyone works physically in Norway, A1 certificates if you post workers, HMS cards in construction — ordered early, they gate site access — and assignment reporting for the contract. The trap is sequencing: several of these depend on each other and the clocks are unforgiving. Run the presence checker, then set up everything in parallel, not in series.