To replace a lost key fob: buy an aftermarket fob on Amazon for your exact year/make/model ($10–$40), then either self-program it using your car's built-in sequence or have an automotive locksmith program it ($50–$80). This is typically 60–70% cheaper than a dealer. Critically, also delete the lost fob from your car's memory — any thief who finds it could still unlock your car until you do.
Step 1 — Delete the Lost Fob from Your Car First
Before anything else, delete the lost fob from your car's receiver memory. Until you do this, anyone who finds your fob can unlock and potentially start your car.
Using the on-board programming sequence (most vehicles)
Most cars let you enter a "fob delete" mode: enter the programming sequence as if you're adding a new fob, but hold the lock button for 10+ seconds instead of just pressing it. The car will delete all previously registered fobs. You then immediately re-register the fobs you still have. See our programming guide for brand-specific steps.
Via the infotainment system (2018+ vehicles)
Many newer vehicles let you manage registered fobs via Settings → Security → Key Fobs (or similar). You can view and delete individual fobs by ID. Check your owner's manual for the exact path.
Via a dealer or locksmith
If your car doesn't support self-service fob deletion, a locksmith or dealer can clear all registered fobs via OBD tools in 10–15 minutes. Cost: $50–$80.
Step 2 — Choose Your Replacement Route
| Option | Cost | Time | Best For |
|---|---|---|---|
| Dealer | $150–$400 | 1–3 days | Luxury/European cars, warranty peace of mind |
| Automotive Locksmith | $80–$150 | Same day | Most vehicles, convenient, on-site service |
| Amazon fob + locksmith programming | $60–$100 | 1–2 days | Most US-market vehicles, best value |
| Amazon fob + self-programming | $10–$40 | 30 minutes | Vehicles with self-programming sequences |
Step 3 — Buying a Replacement Fob Online
To buy the right fob on Amazon, you need two things: your vehicle's year, make, model, and trim, and the FCC ID from your existing fob (printed on the back, usually starting with letters like "GQ4", "M3N", or "HYQ"). Search Amazon for your FCC ID to find an exactly compatible replacement.
For a comprehensive guide to replacement fobs by brand and model, see our Best Replacement Key Fobs guide.
Step 4 — Programme the New Fob
Once you have the replacement fob, programme it using your car's self-programming sequence or have a locksmith do it. Since you already deleted all fobs in Step 1, you'll need to register your remaining fobs at the same time. See the complete brand-by-brand programming instructions in our key fob programming guide.