On 30/04/2021 10:28, Mike Halmarack wrote:
The main door of my flat has 2 yale type locks and a Mortice lock.
The mortice lock key is the only one I ever received.
It's only when the plumber came to do some work that I realised the
possible problem of having two potentially self locking devices on the
door with no key to open them from the outside.
How do I overcome this? Will a Locksmith be able to provide the means
of making these locks fully functional, with minimum cost and work
involved, or will a complete replacement be necessary?

Take them off and repair the holes, just remove the part on the door
jamb so the male part can't latch into anything, remove your male
parts(!), or replace the locks with new. All options are pretty
straightforward.