2021 Tesla Model S Key Replacement

2021 Model S key specs

The refreshed Model S, unveiled in January 2021 and updated again in June 2025, works like a Model 3. Your phone is the everyday key over Bluetooth, key cards are the backup, and a new-style fob adds buttons and passive entry where Tesla offers it. The car stores up to 19 keys, four of which can be fobs. New keys are scanned on the reader in the wireless phone charger, and a fob is swiped downward across the top of the left charger against the center divider.

What's specific to the 2021 Model S

2021 was the first model year of the Model S Refreshed Model S (2021 update). Early-production cars sometimes use different part numbers than later ones, so for a 2021 Tesla Model S we confirm the exact key from the VIN or the old key's FCC ID before cutting anything. It also marks a change from the previous generation: the 2020 Model S used a smart proximity key with push-button start, while the 2021 uses a phone-as-key system, a key card and a smart proximity key with push-button start. Keys from the older car will not work in this one.

A 2021 Tesla Model S is about 5 years old now. Original fob batteries are near the end of their life at this age, so weak range or a "key not detected" message is often a battery before it is a failed fob. Cars this age are often on their second owner, which is when a single remaining key and a request for a spare tend to show up. Smart-key cars like the 2021 Model S can be targeted with relay attacks that extend the fob's signal from inside your home, so keep fobs away from exterior walls or in a signal-blocking pouch, and have any missing fob erased from the car.

Key options for the 2021 Tesla Model S

• Phone as key. Phone keys fail in ordinary ways: a dead battery, an app that logs you out after an update, Bluetooth switched off, or a new phone that hasn't been set up yet. That's why every vehicle with a phone key, including a Tesla Model S, should have a working physical backup, whether that's a key card, a fob or a keypad code. Some phones keep a power reserve that lets the wallet key work for a while after the screen goes dark, but don't count on it in a parking garage. Where your platform allows a locksmith to program a backup fob or card, we can do that on-site; where it doesn't, we'll explain the dealer path.
• Key card. Key cards are tougher than they look, but they do have weak spots. A card carried in a back pocket flexes every time you sit, and a cracked internal antenna simply stops reading. Heat matters too: a card left on the dashboard of a parked Tesla Model S through an inland summer afternoon can warp. Keep the card flat in a wallet slot, and if it shares space with transit or hotel cards, present it alone when it won't read, because stacked NFC cards can confuse the reader. Treat it as a real key, never a spare left in the glove box, since anyone who finds it inside the car may be able to drive away.
• Smart proximity key (push-to-start). Making a new smart key is mostly a programming job. The fob has to match the vehicle's FCC ID, frequency and chip, and then the keyless system must be told to accept it, normally through the OBD-II port. Depending on the platform, that can mean entering a PIN, waiting through a timed security procedure, or on some newer vehicles, using manufacturer online access. When every key is lost, certain models need a module removed and read on the bench. For your Tesla Model S Refreshed Model S (2021 update), we'll tell you which of those applies, and if a step is dealer-only, you'll hear it before we drive out. The emergency blade hidden inside the fob is cut by code during the same visit.

How the Tesla immobilizer works on the Model S

Tesla is the odd one out among the makes we cover, and it helps to know why before you call. The 2008-2011 Roadster is the only Tesla with a metal key. The key turns a starter switch, and the radio fobs built into the keys lock the doors, arm the alarm and disarm it again on Unlock. The 2012-2020 Model S and 2016-2020 Model X brought Tesla's car-shaped fobs, which open the car as you walk up and let it drive once you press the brake. In 2018, KU Leuven researchers showed that early Model S fobs, built around a Texas Instruments transponder running the 40-bit DST40 cipher, could be cloned in seconds. Tesla fitted a newer fob to cars built from June 2018 and added PIN to Drive. The 2017 Model 3 introduced the system every current Tesla uses: your phone acts as a Bluetooth key, RFID key cards are the backup, and most models also offer an optional fob. The Model Y, the refreshed 2021 Model S and Model X, and the Cybertruck all follow it. Each key lives in the car's own key list, added only with a key the car already trusts or through the owner's Tesla account.

• The refreshed Model S fob takes a CR2330 coin cell, not the CR2032 used in 2012-2020 fobs.
• The car always keeps at least one authenticated key card or fob, so the last one in the list can't be deleted.
• A fob is held at the top of the left phone charger against the center divider, front pointing down, and swiped downward to register it.
• Tesla announced in January 2026 that Model S production would wind down, and the last cars were built at Fremont in May 2026.

Getting a 2021 Model S key from the dealer

Keys for this car are added by the owner, not cut or cloned. With a working card or fob, open Controls > Locks > Keys > Add Key, scan the new key on the card reader in the wireless phone charger, then scan a paired key to confirm. With no working card or fob, the owner can authorize a new card from the Tesla app's Security & Drivers screen while in or near the car, on app version 4.29.0 and vehicle software 2022.40 or later. Cards and fobs are sold by Tesla. We don't program them, but we can walk you through the steps.

Refreshed Model S keys are bought from Tesla and paired by the owner or Tesla Service; we don't program them but can help with fob batteries and next steps.

How we help when the key must come from Tesla

Losing every key to a Tesla is less of a crisis than on most cars, provided you can still sign in to the Tesla account the car belongs to. From the app you can open the car and enable keyless driving over the cellular connection, order key cards from Tesla, and pair one through Security & Drivers > Add Key Card while you sit inside. If the car was never transferred to your account after a private sale, or the app can't reach it in a dead zone, Tesla Service is the route. Fobs for the 2012-2020 Model S and 2016-2020 Model X also go through Tesla. A Roadster with no working fob can still be started with its key and the security PIN, but a replacement fob has to come from Tesla. We can't originate Tesla keys, but we can help you figure out which path applies before you lose a day to the wrong one.

1. Get you back into the car. If the car is locked, we open it on site without damage, so you can reach the registration, the VIN plate and anything you need inside.
2. Line up the dealer order. We help you gather what the Tesla dealer will ask for: the VIN, current registration or title, and photo ID in the owner's name. That avoids a second trip.
3. Keep the car where it is if possible. Ask the dealer whether the key can be programmed with the car in place or whether it needs to be towed in. Some brands deliver a pre-coded key; others must program it at the vehicle.
4. Plan for a spare. Once you have a working key, order a second one. Losing the only key on a dealer-only system is the slowest and most expensive situation to recover from.

Why the 2021 Model S needs a dealer key

Why can't a mobile locksmith simply program a new key for a 2021 Model S? Because the newest security architectures keep the secret part of the process at Tesla. The car will only accept a key whose encrypted data was issued for its VIN, and that data comes from the manufacturer through the dealer's parts and service systems. Some owners are told otherwise online; we'd rather tell you plainly before anyone drives out.

What to bring to the dealer

Bring the vehicle registration or title in your name, a matching government photo ID, and the VIN (on the lower driver's side of the windshield and on the door-jamb label). If the car is financed or leased, the dealer may also ask for the lender's paperwork, so call ahead and ask exactly what they need. If any key still works, bring it; adding a key is usually faster than replacing every key.

While you wait for the new key

While the dealer key is on order, protect what you have. If one key still works, keep it indoors and away from the car, and don't hand it to anyone you wouldn't trust with the car itself. If the car is locked with belongings inside, we can open it without damage. If the key has a mechanical emergency blade, ask us about cutting a spare blade by code so you can at least lock and unlock the doors.

What affects the dealer's price for a Model S key

Dealer key pricing depends on the key type (a smart key costs more than a basic remote key), whether the car needs to be at the dealership for programming, the dealer's programming or labor charge, and whether a tow is involved because no working key remains. Ask for the total, parts plus programming plus any tow, before you agree, and ask whether ordering two keys at once lowers the per-key cost.

Avoid doing this twice

Once you have a working key for your 2021 Model S, order a second one while the car's information is already on file. On dealer-only systems, adding a key while one still works is simpler, faster and cheaper than replacing every key after a loss. Keep the spare somewhere you can reach quickly, not in the car, and note where you stored it.

Model S key battery

Battery details for the 2021 Model S: CR2330 (key fob). Swap cells one at a time and match each one exactly; if a key still fails with a fresh battery, the board, buttons or programming may be the problem, which we can test on site.

Common Tesla key problems

• A 2012-2020 Model S with a dead fob battery can still be opened: hold the fob near the base of the passenger-side wiper and press the door handle, then set it against the console just below the low-voltage outlet and press the brake to drive.
• PIN to Drive asks for a four-digit code before the car can be driven. Tesla added it after the 2018 Model S fob cloning research, and it is a sensible extra layer against cloning and relay attacks on phone keys and fobs alike.
• A 2012-2020 Model S holds only three keys, and Tesla warns that any key not present during pairing may stop working. Bring every fob you want to keep, whether you pair at the touchscreen or at Tesla Service.
• Leasing a Tesla? Tesla's manual says a leased car needs the leasing company to add or remove keys, so call the lessor before you order spare cards or a fob, and keep your lease paperwork handy for the conversation.
• Key cards only read when tapped on the right spot. On a Model 3 or Model Y the outside reader is on the driver's door pillar below the camera, and inside it moved from behind the cup holders to the phone chargers on newer builds.

Tips from a mobile locksmith

• Southern California heat is hard on keys. Fob batteries drain faster, plastic housings turn brittle, and rubber button pads crack when a key spends summer afternoons on a dashboard or in a sunny cup holder. Carry the fob with you or keep it shaded, and replace batteries before summer rather than after they fail.
• When a key's head cracks or its blade bends, replace it before it fails. A transponder chip can slip out of a split head, and a bent blade can break off inside the ignition or door lock, turning a simple key replacement into an extraction and repair job. Small symptoms are the inexpensive time to act.
• Make the spare before you need it. Adding a key while one still works is quicker and less expensive than starting from nothing, and it keeps the simpler programming options available. Good moments are right after buying the car, or as soon as one of your two keys goes missing.

Proof of ownership

Not every situation fits the simple case, so here's how we handle the common exceptions. For a leased or financed vehicle, a registration that lists you as the registered owner or lessee works with your ID. If you just bought the car, bring the signed title or bill of sale along with your ID. For a company or fleet vehicle, we need written authorization from the business plus the driver's ID. If the car belongs to a family member, the registered owner should be present or provide signed permission and a copy of their ID. Rental vehicles go through the rental company.

Need a 2021 Tesla Model S key?

Call Julian's Locksmith at (951) 903-3193 if you're locked out of a 2021 Tesla Model S or need help preparing a dealer key order. We'll tell you plainly what we can do on site and what has to go through Tesla.