Ejari is Dubai's mandatory tenancy contract registration system, run by the Dubai Land Department. Without a registered Ejari certificate, several everyday parts of moving into a new home simply will not go through.
DEWA connection is the most immediate blocker. Dubai Electricity and Water Authority requires an Ejari certificate to open a new account at your address, so if your Ejari isn't registered yet, your move-in date should not be earlier than your DEWA activation date.
Building NOCs for move-in also typically ask for the Ejari certificate alongside your tenancy contract, especially in towers with strict move-in scheduling. Landlords or agents usually handle registration, but it's worth confirming before your move date is fixed, not after.
Ejari also matters beyond the move itself: it's commonly required for visa sponsorship renewals tied to a residential address, and for setting up other utility or telecom accounts that verify residency.
Practically, build a few days of buffer between signing your tenancy contract and your planned move-in date, enough time for Ejari registration and DEWA activation to clear before the truck arrives.