A short-term rental turns over guests every few days, and each one is a stranger who needs to get in and then be kept out again. Traditional keys do not handle this well: they get copied, lost, or simply kept by a previous guest. A shared permanent code is no better, because the code that opens the door for this week's guest also opened it for last week's. Security in an STR is mostly a matter of treating every stay as its own access event.
One unique code per stay, nothing physical
The most important rule: every guest gets a credential that exists only for their stay, and nothing physical ever changes hands. Generate a fresh code for each booking, tied to that guest's check-in and check-out times. Let it auto-expire on check-out, so access stops without any host action — the guest cannot forget to leave, and cannot return later. Never reuse a code across guests; reuse is exactly what makes codes leak across stays. Avoid obvious patterns too — a code derived from the room number or check-in date is guessable, so use the random codes the platform produces.
Issue access digitally, as a passcode or mobile key, so no physical key is ever handed over. Keep the mechanical override for emergencies only, stored securely and never given to guests. A lockout is the one situation it is there for. The mechanism behind this is explained in temporary access codes for guests.
The audit trail
When something goes wrong in a rental — a noise complaint, damage, an entry no one expected — the question is always who was in the unit, and when. A smart lock answers that precisely. Every entry is logged with a time and a credential, and with per-stay codes that credential ties to a specific guest. The record shows whether a guest entered when they claimed, or whether someone used a code outside the booking window. For cleaners and maintenance, separate time-boxed credentials prove exactly when service staff were on site. That record is a large part of why a smart lock beats a basic keypad. It verifies every opening, with a name and a time attached.
Offboarding is half the job
Secure onboarding is half the work; clean offboarding is the other half, and the part most often skipped. Guest codes are supposed to expire at check-out — verify it rather than assuming. Cleaner and service credentials should be time-boxed to the turnover window and rotated regularly, not left standing. Any team member who leaves the operation is revoked the same day, rather than waiting for the next batch. And once a month, audit for stale credentials: a code that should have expired but did not is a common finding, and a quick fix.
The owner account
The host's own account controls every door. Compromise it and every door it controls is compromised. Use a strong, unique password and turn on two-factor authentication. Never share the owner login with cleaners or co-hosts — give them their own scoped accounts instead. Stay wary of phishing, because booking-platform impersonation is a common way attackers reach host credentials. Keep the gateway and app updated too, since the account layer and the device layer protect each other.
Hardening the door itself
Digital security is only useful if the door itself holds up. A door sensor adds a check that credentials alone cannot provide: it detects a door that opens without a valid credential, whether that is a forced entry or a guest leaving the door ajar. Check that the bolt fully throws and the strike is aligned, because a half-engaged bolt is a pry target. Use weather-rated hardware if the door is exposed, and keep batteries fresh while heeding low-battery alerts — a dead lock forces insecure workarounds. For choosing hardware that supports all of this, the guide to access control for hotels and short-term rentals walks through it.
What to run, and how often
Some of these checks belong between every booking, others once a month. Splitting them that way keeps the per-stay work small.
| Check | Every stay | Monthly |
|---|---|---|
| Fresh per-stay code generated | Yes | — |
| Previous code confirmed expired | Yes | — |
| Cleaner credential time-boxed | Yes | Yes |
| Stale credentials audited and pruned | — | Yes |
| Owner password and 2FA verified | — | Yes |
| Door sensor armed and reporting | Yes | Yes |
| Batteries and low-battery alerts | — | Yes |
| Firmware and gateway updated | — | Yes |
None of this is exotic. It is what a well-configured smart lock does by default, and it is also the practical difference between a professional listing and an amateur one. Run the per-stay column between bookings and the monthly column on a fixed date. Most hosts do not get this far, and doing so puts a listing's access security on solid ground.