The choice of lock is a key factor when selecting a safe. Depending on the usage profile and risk level, a safe can be fitted with key locks, mechanical combination locks, electronic code locks, or a combination of both. Electronic locks often provide additional features such as programmable user codes, time delay functions, or integration into an alarm system. Where possible, a combination lock (for example code + key) is preferred over a key-only lock: keys are bulky, difficult to keep secure, and if lost or stolen, they grant immediate access to the safe. Certified safes and fire-resistant cabinets must also be equipped with certified locks according to EN 1300. This standard classifies locks into Classes A, B, C and D, based on their resistance to manipulation and burglary attempts.