Battery flat.Central locking not working.Have ignition key, which doesnt work in door locks.Is this right key and its just that the locks are stiff for not being used, or is ignition key diff to door?

Try a new battery in the KEY

Lock ALL DOORS, Disconnect the Battery... Wait 2-3 minutes and connect the battery and it should reset itself. Make sure all doors are LOCKED...

AND that you have a KEY to open the door in case it does not work.

Your remotes may need to have batteries replaced and re-programmed.

Providing central locking works when you insert key in lock,try programming keys
Enter car make sure all doors/windows are shut
Switch ignition on and off,remove key
PRESS AND HOLD UNLOCK BUTTON ON KEY
Press lock button on key 3 times whithin 10 seconds and release unlock
Central locking will lock/unlock rapidly to confirm reset
If your key is the type with bmw logo in the middle battery replacement is not possible,as it charges as you drive

Unlock vehicle. Enter vehicle. Close driver's door. Switch ignition ON and OFF. Remove ignition key. Press and hold unlock button. Press lock button briefly 3 times within 10 seconds keeping unlock button depressed. Release unlock button. Some models: LED flashes slowly for 10 seconds. Some models: Central locking system locks and unlocks rapidly to indicate correct programming. Repeat above procedure if central locking system does not work and LED does not flash or LED flashes continuously.

If your key will not manualy open door
Try it in boot lock,it might activate central locking

fuse 56 and 57 control central locking,the issue is caused by surges typically in the front door lock actuators, normally at a dealer they would replace fuse 56 and 57 with a 20a mini fuse and if still occuring repl the door lock(s) that dont work or typically both front, first replace fuse 56 and 57 with 20a fuses as were too small from factory and than operate ten to 15 times, if it doesnt work at first dont panic,let the car go to sleep which takes about 16 min and than try again this problem has nothing to do with the key fob or the lock unlock button inside,also the fuses are located behind the glove box just rere the access panel and they are found at lower left section

Had same trouble with my 406, fixing no problem, with new battery in fob, insert into ignition, turn key, BUT DO NOT START ENGINE, hold button for about 10 seconds release button and remove key from ignition, then try and see if doors lock on remote, if not try again, had to do this a couple of times, and it worked, sorry to say that now my key fob button has completely fell apart, through ware and tare

leave ign off with key out 3mins disconnet battery 5 mins reconnett and press lock/ unlock repeatedly until locks cycle through to re sync try this any probs come back to me