Spare keys are important, but where you keep them can either protect you or put your home at risk.
The classic hiding spots—under the doormat, in the shoe rack, on top of the door frame—are exactly where strangers will look first. Avoid these completely.
Better options include leaving a spare with a trusted neighbour, close friend or nearby relative. This way, the key isn’t physically near your door at all.
Inside the home, keep extra keys in a fixed, not-so-obvious spot: a small box in a cupboard, a labelled hook inside a wardrobe, or a drawer that everyone at home knows. Avoid leaving keys in plain sight right next to the main door.
If your society has a secure, staffed office or gate, sometimes a labelled and logged key can be stored there for emergencies—depending on how trustworthy the system is.
Key safes with combination locks can work if mounted discreetly and if the code is changed occasionally.
The goal is to balance convenience and safety, not to make your main lock meaningless.