Lock and door security problems

The door has shut behind you, the key is inside or lost, and you are standing outside with no way in.

The key has broken, leaving part of it inside the barrel, and the rest is in your hand.

The key goes round freely — sometimes round and round — but nothing moves and the door stays shut.

The uPVC door closes, but the handle will not lift to throw the bolts, or it lifts and the key still will not turn.

The front door will not stay shut, the latch does not click home, or the snib no longer holds the latch back.

Your keys have gone missing or been stolen, and you do not know who has them or whether they can find your address.

Your policy asks for British Standard locks and you have no idea whether the locks on your doors qualify.

Your uPVC or composite door has a barrel lock sticking out past the handle, and you have read that they can be snapped.

You have just moved in, you have a handful of keys from the agent, and no idea who else still has one.

Someone has been at the door — the cylinder is broken, the frame is split, or there are marks around the lock.