Tell us what changed
A problem that appeared after a door was painted or new weatherstripping was installed may need a different assessment from a handle that has been loosening for months. Say when you notice the fault, which key you use and whether the door has to be in a particular position.
Do not force a bending key or keep using a damaged fitting. If a piece has broken, keep it for identification. Clear photos of the door, lock and frame can help describe the job, without taking the mechanism apart to show us inside.
A working cylinder is only part of a working door
The key may operate normally while the latch fails to catch. A bolt can move freely with the door open and meet pressure once it is closed. These observations do not provide a diagnosis on their own, but they help explain why simply copying a key may leave the original problem in place.
For a business entrance, mention a closer, exit device or electronic release connected to the same door. Those parts affect its ordinary use. Repairs should be scoped around the actual fault, including any work that needs a different trade or building approval.
Repair, rekey or replace?
Repair addresses a fault. Rekeying changes which mechanical key works. Replacement introduces different hardware. You may need one of those steps or a combination, but they should not be treated as interchangeable names for a single job.
Ask which part is being repaired and why any new hardware is proposed. Discuss the estimate before authorizing additional work. With an older fitting, part availability and condition affect what can be kept. Once finished, use the lock yourself in its everyday position and raise any remaining resistance before the visit ends.
Should I buy a new lock before arranging a repair?
It is usually better to establish the fault and fit first. If you already have a replacement, keep its model details and packaging. The existing door preparation may not match the new hardware.
Can I ask about just one troublesome door?
Yes. Call 214-613-0113 and describe that door, its Dallas location and what happens when you try to use it. The repair does not have to become a change to every lock.