Start with the essential details
Say whether it is a house, apartment, business or vehicle. Explain where the key is, whether it broke and whether another lock is engaged. Give the complete address and unit, or the parked vehicle location. This is enough to begin; do not dismantle the lock or try to force the opening before calling.
At a shared or managed building
A common entrance and your own unit door may be controlled separately. Tell us which one is preventing access and contact the responsible manager where appropriate. University-controlled buildings should involve the relevant facilities or security team. Have information ready to establish authorization; knowing the address alone does not establish a right to enter.
At a car or garage
Provide the make, model and year and explain whether the keys are inside or lost. Include the garage level, vehicle description and accessible entrance. If all keys are missing, say so at the start because a replacement-key request requires a separate compatibility discussion.
Keep the next step simple
Wait in a safe place, clear of traffic, and keep your phone available. Do not climb to another entrance or keep forcing a damaged key. If there is immediate danger, contact emergency services. A locksmith call is for access assistance, not a substitute for an emergency response.
Before agreeing to the work
Ask about the visit and labor charges and how any required parts would be handled. The condition of the hardware can affect the available approach, so do not assume a particular outcome before assessment. If the proposed scope changes, confirm it before authorizing additional work.