01Useful details when you are outside
Say whether the keys are inside, lost or with someone who can bring them. Mention any key left in the inside of the lock and whether a second lock is engaged. If you live behind a communal entrance, explain which door is blocking access. You may need to establish your authority to enter, especially when someone is arranging the visit on your behalf.
02Ask about the whole job, not just entry
Non-destructive opening is preferred where suitable, but the lock and door condition determine what is possible. If the mechanism has failed, getting inside may be followed by a repair discussion. If keys are missing, a replacement may be worth considering. Ask what the initial quote covers and agree any additional hardware or work before it proceeds.