Begin with the key you still have.
If a key works, say so. Note whether it starts the vehicle, operates its ordinary locks and has buttons you use. If a second key is unreliable, describe its behavior separately. Avoid treating two different faults as a single request for a duplicate.
For a lost last key, include the make, model and year and the vehicle’s actual location. A compatible key and the work required depend on the particular vehicle. This page does not promise that every make, model or fob can be handled.
A spare for the everyday.
A school run, a shopping trip and a walk by the lake can each end with a search for the key you had earlier. Think about who may need the vehicle and where an authorized spare could be kept securely. A spare locked inside the same car may not help when access is the problem.
The spare-key planning guide separates household decisions from the technical compatibility check. It also helps keep a car spare distinct from the keys used for the front door or garage-entry door.
Check the proposed work before agreeing.
Ask whether the request can be handled for your vehicle, what information or proof will be needed, and what the estimate includes. If a key is present but the car does not respond, explain that instead of assuming a replacement will cure the issue.
If the only problem is that a usable key is inside a locked car, start with the automotive access information. The FAQ page covers common preparation questions without asking you to diagnose the car.