Car keys and fobs

• The make, model and yearIt decides the key type, and whether a locksmith can do it at all
• Whether you still have one working keyThe single biggest factor in both the price and the time
• Proof of ownership and identificationOwnership papers and a licence
• What kind of key it isA plain key, a chipped key, a remote head, or a proximity fob

General guidance, not advice on your own situation. The person you hire decides what applies to it.