Changing your address is a list, not a feeling that you live here now. USPS, the DMV if you drive, banks, payroll, insurance, voter registration, and the front desk are separate. If you only do the post office, your packages will still go to the old walk-up while the desk is asking who you are.

The building
Tell the concierge your name, your residence number, and the date you take keys. That is how mail, lockouts, and vendor access work. If a roommate is on the lease, their name belongs in the same conversation. A package addressed to a name the desk does not have will sit or bounce.
USPS change-of-address does not automatically teach the package room your nickname. Use the name on the lease.
The rest of the list
File USPS change-of-address online or at a post office. Update your employer. Update health insurance and any prescription delivery. If you vote in New York, update voter registration. If you have a car, DMV and insurance need the new address. Do not wait for a missed jury summons to remind you.
Accounts with two-factor codes tied to a phone number are easier than accounts still tied to a doorman who already forgot you. Do the banks in the first week, not after a card is declined because a fraud filter saw a new ZIP.
Do it after you have a number
Do not change the address until you know the residence number you will actually occupy. Filter listings, tour, then use 222 East 34th Street plus that number. Call (212) 684-3222.
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