What are common reasons shopfront locks fail?

A shopfront fault can involve the lock, the door or frame, or connected access hardware, and a short description cannot establish the cause. The Door & Hardware Federation says maintenance needs depend on the type and use of a door or gate and that the person responsible for the premises should ensure essential maintenance is carried out. Do not force the entrance or compromise an escape route.

Note what the key and handle do, whether the door remains secure, and arrange an assessment by someone authorised to work on it.