Is the key inside, missing or stuck?
These are different problems. A key left on the kitchen counter calls for an access conversation. A missing key may also mean you want to change who can use the lock. A key that will not turn, or has broken in the lock, needs a different assessment again.
Describe what happened without forcing the key or pulling on the door. If you still have a working key for another entrance, mention it. You do not need to diagnose the lock before making the call.
At home or in a rental
Have the complete street address and unit number ready. Say whether it is your private front door, an interior room or a shared building entrance. For a rental, contact the landlord or property manager when their approval is needed.
Be ready to establish that you are entitled to access the property. If your identification or paperwork is inside, explain that at the beginning so the person handling the request can discuss the next step.
With a car or a business door
For a vehicle, give the year, make and model, and say whether the keys are visible inside or are missing. A parking location should describe the car, not just the café or store where you are waiting.
For a business, identify the particular entrance or suite and the person who can authorize the work. A shared access system or building-controlled door may need the property manager involved.
Before you arrange help
Ask about availability, the expected attendance arrangements and what the estimate covers. If the proposed work changes after the door is inspected, ask for the updated scope and cost before approving it.
A lockout involving a child, someone in immediate danger or another urgent safety risk needs emergency services first. For an ordinary lockout, a clear location and a simple account of what happened are the best starting points.