For landlords, locks are a turnover task and a liability issue rolled into one. Here's how to handle the common scenarios cleanly.
Between tenants: rekey, every time
Non-negotiable. Rekey every unit lock between tenants — front door, back door, mailbox, storage. It's fast, inexpensive, and it's the only way to be certain the previous tenant's key circle is retired. Build it into your turnover checklist alongside painting and cleaning.
After an eviction: act promptly
Once you have legal possession, rekey immediately — before showing the unit, before contractors start work. An eviction is exactly the scenario where unreturned keys are most likely to be misused. Document the rekey with your locksmith's invoice; it's part of your paper trail.
Roommate and sublet situations
When the leaseholder stays but occupants change, rekeying is still wise — the departing occupant's keys are out of your control. It's cheap insurance and tenants appreciate the diligence.
Ending key chaos permanently
If you manage multiple units, install a system: a master key structure (one building key for you, individual keys per unit) on a restricted keyway (no unauthorized copies, ever). Turnover becomes a single-cylinder rekey instead of a scavenger hunt. We design and maintain these systems for Manhattan landlords — one call, key control solved.
A note on the law: lock changes must follow NYC housing law — never change locks to force out an occupant; that's an illegal lockout with serious penalties. When in doubt, talk to your attorney first, then call us at (212) 671-0532 to execute what's lawful.