Dealer or locksmith for a car key? Sometimes the answer is the dealer.

Very new models. When a manufacturer releases a new model or a new generation of security system, it can take time before independent programming equipment supports it. If your vehicle is brand new, there is a chance only the dealer can program keys for it for a while. We will check before we come out.

Certain brands and restricted systems. Some manufacturers, particularly some European luxury brands, restrict key programming for certain models so that it goes through their own systems. In those cases the dealer may be the only realistic option for a new key. Our European car keys page covers what we can and cannot do there.

Warranty coverage. If your key or its electronics failed while the vehicle is under warranty, the dealer may replace it under that warranty. Check before paying anyone else.

A deeper electrical fault. If the problem is not really the key but the car's immobilizer module, body control module or wiring, a dealer or a qualified auto electrician is better placed to diagnose and repair it. We can often tell whether the car is recognizing a key, and if the fault is beyond the key, we will say so.

You simply prefer it. Some owners want a genuine manufacturer key programmed by the manufacturer's dealer, full stop. That is a legitimate preference, and if the car is drivable and you have time, it is a reasonable choice.

There are two broad kinds of replacement key. Genuine keys come from the vehicle manufacturer or its approved supplier, and are the same as the key the car was sold with. Aftermarket keys are made by other companies to work with the same vehicles.

Good aftermarket keys work well and are widely used. Poor ones can have weak shells that crack, buttons that wear quickly, or remote range that falls short of the original. The quality varies a lot between suppliers, which is why it is worth asking what you are getting.

Dealers generally supply genuine keys. Locksmiths may offer either. We tell you which we are using, and where a genuine key is available and you prefer it, we can usually source one. What matters most is that the key is well made, programs correctly and fits your vehicle properly.

Some remote keys and smart fobs from the manufacturer are locked to a vehicle once programmed and cannot be reprogrammed to a different car. Buying a used fob online to save money often ends with a fob that cannot be used. If you are thinking about supplying your own key, ask first whether it can be programmed. The lost key fob costs guide goes into the factors that decide cost.

At the dealership. You call the service department, give the vehicle identification number and prove ownership. Some dealers can cut a blade from the VIN using the manufacturer's code records, and some will need to order the key or fob, which can take days for less common models. Once the key arrives, the car needs to be at the service department for programming. If you still have a working key, you drive it in. If not, you arrange a tow. Programming itself is usually quick, but the whole process, from the first call to driving away, often runs across several days because of ordering and appointment slots.

With a mobile locksmith. You call, give the year, make and model, and describe what happened. A good locksmith will confirm on the phone whether they can handle your specific vehicle and what the job involves. At the car, they check your identification and ownership documents, then cut a key, either from a code, by decoding the locks, or by copying an existing working key. They connect programming equipment to the vehicle, add the new key to the car's memory and test it: locks, remote functions and starting. If you are adding a key, they will usually test your existing keys still work afterward.

Either way, test everything before the technician leaves or before you drive off the lot. Lock and unlock with the remote, open the trunk if the remote does it, start the car several times, and check that your other keys still work. Problems are much easier to sort while everyone is still there.

Keep the paperwork. A receipt that lists the key type and the number of keys programmed is useful if anything goes wrong later, and helpful when you eventually sell the car.

Dealerships across New Castle County cluster along the main corridors near Wilmington, Newark and the Route 13 and Route 40 areas, and in Kent County mostly around Dover. If you live in Townsend, Harrington or one of the smaller Kent County towns, a trip to the dealer may be a long drive, or a long tow if you have no key.

That geography is one of the biggest practical reasons people in our area choose a mobile locksmith. A lost key in a parking lot in Milford or at a farm outside Hartly is a very different problem when the solution can come to you.

At the same time, Delaware drivers include plenty of people with new vehicles under warranty and plenty of European brands, particularly in northern New Castle County. For those owners, the dealer is sometimes the right call, and we would rather tell you that on the phone than come out and fail.

Students and staff at the University of Delaware and Delaware State University, and personnel at Dover Air Force Base, often drive vehicles registered in other states or bought far from here. That does not change the process. What matters is proof of ownership and whether the vehicle's system is supported. Bring the registration or title, whatever state issued it, and we can check the rest.

Finally, remember that the choice does not have to be all or nothing. Plenty of owners have their dealer handle warranty and major repairs, and call a locksmith for a lockout, a spare key or an urgent all keys lost situation. Use whichever route fits the problem in front of you, and ask both the same questions about cost, key type and what happens if it does not work.