A working spare changes the starting point
If you still have a key that starts the car, say so. Making another working key may follow a different process from an all-keys-lost job. A spare remote that only unlocks the doors is useful information, but it is not the same as a fully working key.
Write down the year, make and model. Mention any unusual history, such as changed locks or a replacement ignition. Photos and part numbers can help with initial checks, but an exact match must be confirmed for the vehicle.
Decide which functions matter
Some keys are simple metal blades. Others include a chip, remote controls or proximity electronics. A remote-head key combines more than one function in one housing. The price and work depend on what is actually supplied and configured.
Ask whether the estimate includes the blade, programming and the buttons you expect to use. If the fob has a separate emergency key, ask about that too. You should not discover afterward that only one part of the original key's job was included.
Already bought a replacement?
Keep the packaging and the listing. The external shape is not enough to establish compatibility. Part numbers, electronics and the vehicle system can differ even when the shell looks identical. Used or previously programmed parts may introduce other limitations.
Explain what you have before arranging the visit. Support for customer-supplied parts must be checked. Sometimes a different part or another service route is needed; it is better to understand that before paying for work that cannot produce the required result.
When the old key is missing
Tell the service provider whether you want to discuss the missing key's future access. Electronic key recognition and a physical door lock are separate systems, so replacing a fob does not automatically answer every question about the old key. The options depend on the vehicle.
Once the replacement is ready, check the agreed door, start and remote functions. Store the spare away from the everyday key. Read the quote guide if you are comparing services, or the car locksmith overview if you are still working out whether the problem is the key, remote or lock.