Between May and October an Algarve holiday flat can change guests twenty times. Every changeover is a moment when the key leaves your control — and nearly every security problem in short-term rentals starts right there.
Option 1 — External key safe
The most common and the cheapest. It works well if the safe is a decent one, properly fixed to solid wall, and the code is changed on every checkout.
The weak point is human: the code never gets changed and ends up being passed around guest WhatsApp groups. If you use a key safe, change the code religiously between bookings.
Option 2 — Rekeyable cylinder
A cylinder that accepts reprogramming with a service key: insert the reset key, turn it, and from that moment the old keys stop working. It takes under a minute and needs no locksmith.
This is our recommendation for anyone running two to six units. The upfront cost is higher, but it removes the recurring expense of swapping cylinders and the anxiety of not knowing how many copies are out there.
Option 3 — Master-key system
Each unit has its own key and the manager carries one key that opens everything. For a whole building, or more than six units, it saves the most time day to day.
Rule of thumb
If a key goes missing with the unit number on the fob, change the cylinder the same day. That is the scenario where a lost key stops being an inconvenience and becomes an exposed address.
What we tell Algarve managers
- Never label a key with the address or apartment number.
- Keep a written record of how many keys exist per unit.
- Service the cylinders at the start of each season, before the July peak.
- Save a locksmith's number before you need it — two in the morning in August is not the time to be searching Google.
