Ford Mustang 2015-2023 Spare Key — Annetta TX
Spare key for a 2015-2023 Ford Mustang in Annetta TX. Why S550 cars split between keyed and push-button, what a second key costs, and why a garage-kept car still needs two.
Ford Mustang 2015-2023 Spare Key — Annetta TX
Mustangs are the cars most likely to be driven on one key, and the reason is understandable: a garage-kept weekend car does not feel like it is at risk. Then the single fob gets left in a jacket at a Weatherford restaurant, or goes through a wash cycle, and a car that has never given trouble becomes a car that cannot be moved. Call or text (817) 813-9396 for Mustang spare keys in Annetta, Weatherford, Aledo, Willow Park, Benbrook and Fort Worth.
Quick Answer
A spare key for a 2015-2023 S550 Mustang is made by supplying the correct key or proximity fob for your car, cutting the blade to your VIN where applicable, and registering it to the car's PATS immobilizer so the engine will be authorized to run. As of August 2026 a spare typically runs $180 to $380 depending on whether the car is keyed or push-button. The same key made after every key is lost costs roughly double.
Mustang Spare Key Pricing in Annetta TX
| Service | Typical Price Range | Notes |
|---|---|---|
| Spare transponder key, keyed ignition | $180–$300 | Laser cut plus programming |
| Spare proximity fob, push-button | $260–$380 | Fob plus programming |
| Program a fob you supply | $85–$155 | If the part number matches |
| All keys lost | $320–$600 | Origination, longer procedure |
| Emergency blade cut only | $60–$110 | Door entry, no programming |
| Fob shell / worn button rebuild | $50–$110 | Keeps programmed electronics |
Disclaimer: Ranges only. Model year, trim, key part number and how many working keys remain all move the number. Call or text (817) 813-9396 with your VIN.
Which S550 Do You Have?
The sixth-generation Mustang covers 2015 through 2023 and it did not stay electrically identical across those years. The first thing to establish is the ignition.
Keyed cars have a cylinder the key turns. The key is laser cut with a transponder credential inside the head.
Push-button cars have a START/STOP button and a proximity fob the car reads passively. There is a hidden emergency blade inside the fob for the door, but the ignition never sees it.
Beyond that, part numbers moved during the generation, notably around the 2018 refresh. Two Mustangs from either side of that line can look identical in a driveway and take different fobs. The VIN settles it before anyone buys anything, which is why it is the first question on the phone.
Why a Weekend Car Still Needs Two Keys
The counterargument owners make is reasonable on its face: the car sits in a garage, the key lives on a hook, nothing ever happens. Here is the arithmetic that changes minds.
Spare, on your schedule: the car is in the garage, the appointment is when you choose, and you pay the spare-key figure above.
All keys lost, on the car's schedule: the key must be originated from vehicle data rather than copied, ownership has to be verified before any work starts, and the procedure runs considerably longer. On a car parked away from home, add recovery. The bill lands near double, and it arrives on a day you did not plan for it.
There is a second, less obvious argument. A car driven infrequently is a car whose single fob battery sits at a low state of charge for long stretches, and whose owner has no second fob to test against when behavior gets strange. Two keys are a diagnostic tool as much as a backup — if one works and the other does not, you have learned something instantly.
What Happens at the Appointment
Cutting
Modern Ford keys are laser cut, with the milled track down the flat of the blade rather than a jagged edge. The blade is cut to code derived from your VIN with equipment carried in the service van, producing a key that matches the lock as built rather than copying wear from an original that has been in and out of a cylinder for years. The difference between the two cutting styles is covered in our laser cut versus edge cut car keys guide.
Programming
The transponder credential is written into the car's trusted key list. Bring every key you own, including any you think is dead — Ford procedures commonly affect the whole set, and a fob left at home can quietly drop out. A flat battery is easy to test on site and a working transponder is worth keeping.
Proving it
Lock, unlock, trunk, remote start if fitted, and an actual engine start with the new key while the original is out of the car entirely. That last step is the one that gets skipped by people who should not be doing this work.
When a Mustang Fob Stops Working
Four patterns, and they lead to different bills:
Weak fob battery. Intermittent detection, worse in cold weather, better when the fob is held against the start button. The cheapest thing on the list — rule it out first.
Failed or water-damaged fob. One fob consistently fails while the other works. That is a fob problem and a replacement or rebuild solves it.
Both fobs failing identically. That points away from the keys and toward the receiving side — module, antenna, or wiring. A third fob does not help. This is exactly the scenario where owning a second key pays for itself in diagnosis alone.
Crank and immediate die. Classic immobilizer refusal: the engine proved it runs, then authorization failed. If a security indicator is showing on the cluster, the pattern in our immobilizer reset and security-light no-start guide applies. The wider Ford context sits in our Ford Expedition key fob programming guide, which walks the same PATS logic on a different body.
Buying a Mustang Fob Online
It can work. The things that go wrong:
Wrong part number. Fob frequency and chip type shifted within the S550 run. A fob that looks correct can be electrically wrong for your car.
Used fobs that are locked. A fob pulled from another Mustang may or may not accept a new identity. Some do. Some are permanently bound to the donor and are scrap.
Uncut blade. Standard on aftermarket listings; just budget the cut.
Send the part number for a check before you buy. It costs nothing and prevents paying for a visit to program something that cannot register.
Mobile Service Across Parker County
Cutting and programming equipment travels, which matters on a car people are reluctant to have towed. Work is done in your garage or driveway — Annetta, Weatherford, Aledo, Willow Park, Hudson Oaks, Benbrook, Fort Worth and the 76008 area.
Frequently Asked Questions
How much is a spare key for a 2018 Mustang?
As of August 2026, roughly $180 to $300 for a keyed car and $260 to $380 for a push-button car, including the blade cut where applicable and programming. Part numbers changed around the 2018 refresh, so the VIN is what pins the figure down.
Can I program a second Mustang key myself?
No. The transponder credential has to be written into the car's trusted key list with programming equipment. Some owners find onboard sequences described online for other Fords or older model years, but for the S550 as sold here a tool is required.
Do I have to bring my original key to get a spare?
Yes, and bring any others you own. Having a working key present keeps the job in the spare-key category rather than the far more expensive all-keys-lost category, and Ford procedures commonly rewrite the whole trusted set, so absent keys risk being dropped.
What if I already lost the only key?
Then the key must be originated from the vehicle rather than copied. It takes longer and costs roughly double a spare, and proof of ownership — registration or title plus matching photo ID — is required before work begins. It is still a mobile job done where the car sits.
Will an aftermarket fob work in my Mustang?
Sometimes. The two failure modes are a part number that is wrong for your specific configuration and a used fob permanently locked to a previous vehicle. Send the part number for verification before purchasing.
Make the Spare While the Car Still Starts
Every all-keys-lost Mustang call started as a Mustang with one key on a hook. Call or text (817) 813-9396 with your year and VIN for a spare-key quote.
Article written by the Annetalocksmith Automotive Locksmith Team. Reviewed by a working automotive locksmith technician.