Main dealer or auto locksmith for a new key?
Both can give you a working key. The difference is mostly time, travel and price, plus a short list of cars where the dealer is the only option.
Getting the car there
A dealer works at the dealership. If you have a working key that is only an inconvenience. If every key is lost, the car has to be recovered to them, and that is a cost on top of the key. A mobile locksmith comes to the car.
Waiting time
Dealers usually order keys from the manufacturer against the car's chassis number. That can take days, and then you need an appointment for the programming. A locksmith normally carries the key or gets one quickly, and cuts and programs it in one visit.
Price
Dealer keys are genuine parts at dealer labour rates. A locksmith can usually offer the same genuine key or a cheaper aftermarket one. Get both prices and compare like with like.
When the dealer is the right call
Some of the very newest models, and some makes after a certain year, have keys that only the manufacturer can supply. Mercedes cars after 2014 are an example. A good locksmith will tell you that at the start. Warranty is rarely a reason on its own. Having a key made by an independent locksmith does not normally affect a manufacturer warranty.
Whoever you use
Expect to show ID and proof the car is yours. Ask whether lost keys will be deleted. Ask for the total price before work starts.
Want a price for your vehicle?
Make, model and year is all we need to start.