Lexus IS & GS Smart Key Replacement Cost in Farmers Branch & Irving TX (2026)

Short answer. As of October 2026, replacing a smart key for a Lexus IS or GS in Farmers Branch or Irving costs $300 to $500 for a spare with a working key present, and roughly $100 to $200 more when every key is gone and the Smart Access system has to be reset. Both sedans have used push-button start on every trim sold here since 2006, so there is no cheaper blade-key version to fall back on. Mobile service during business hours is included, and we confirm the exact figure against your VIN before we roll. Call or text 817-842-1751.

Why the IS and GS Are a Single Category

The IS and GS are the two rear-wheel-drive sedans in the Lexus lineup, and for key work they behave as one family. Both adopted the Smart Access proximity system across every trim with the generations that arrived for 2006. Both went through the same immobilizer generations on roughly the same schedule. Both were sold in large numbers across north Dallas County, which is why Farmers Branch and Irving produce a steady run of calls for them even though the GS left the market after 2020.

That shared history is useful: if you know the year of your sedan, you know the job. This guide gives you the 2026 price by generation, explains what the Smart Access system does to the procedure, and covers the two details owners most often get wrong, the all-keys-lost reset and the hybrid battery.

Smart Key Cost by Generation

Model	Model years	Key type	Typical mobile cost, one key	All keys lost add-on	Notes
IS (second generation)	2006–2013	Smart Access fob	$300–$500	$100–$200	Includes IS250, IS350, IS F; earlier immobilizer generation, mature procedure
GS (third generation)	2006–2011	Smart Access fob	$300–$500	$100–$200	Includes GS300, GS350, GS430, GS460; the GS450h hybrid uses the same fob
GS (fourth generation)	2013–2020	Smart Access fob	$300–$500	$100–$200	Includes GS350, GS200t, GS300, GS F; GS450h hybrid same fob
IS (third generation)	2014–2020	Smart Access fob	$300–$500	$100–$200	Includes IS200t, IS250, IS300, IS350; newer immobilizer generation
IS (third generation, updated)	2021–2026	Smart Access fob	$300–$500	$100–$200	Includes IS300, IS350, IS500; newest security generation, connectivity and voltage matter during programming
Either, second key in the same visit	Any	Smart Access fob	Lower than the first; quoted on the call	Not applicable
Either, locked out with the fob inside	Any	Any	$75–$145	Not applicable	Non-destructive entry

Reading the table. The all-keys-lost column is an add-on to the price beside it, not a separate total. "Smart Access fob" means the proximity key you keep in a pocket; the small emergency blade inside it opens the driver's door when the fob battery dies and is cut as part of every job. Figures are for mobile service during business hours. After-hours calls may carry a premium, which we disclose before dispatch, in line with the Federal Trade Commission's guidance that every fee belongs in the estimate before work begins (ftc.gov).

What Smart Access Changes About the Job

On a conventional transponder key, the chip in the key head is read by an antenna ring around the ignition when you insert the key. On a Smart Access Lexus there is no ignition slot. The fob answers low-frequency signals from antennas in the cabin and doors, the smart key control module confirms the fob's identity, and only then does it pass authorization to the immobilizer and the engine controller. Immobilizers of this kind are the reason the IS and GS sit low on theft-loss tables, and the Insurance Institute for Highway Safety's data has shown that effect across the Lexus lineup for years (iihs.org). The National Highway Traffic Safety Administration's theft-prevention standard is the regulatory basis for the system (nhtsa.gov).

For key replacement, three consequences follow.

Registration, not cutting, is the main job. The fob must be registered to the smart key control module. On the 2006 to 2013 sedans that is a well-understood diagnostic-port procedure. On the 2014 and newer cars the handshake is stronger, and on the newest IS it depends on an authenticated session and current security credentials, which independent locksmiths obtain through programs run by the National Automotive Service Task Force after vetting (nastf.org).

A registered fob stays registered. Lexus fobs are tied to the vehicle they were registered to. A used fob from another car generally cannot be registered to yours, which rules out most secondhand listings. Our guide to replacement fob cost by source explains why refurbished is not the same as reusable.

All keys lost means a reset. With no working fob, the smart key module has to be returned to a state where it will accept a new registration. On the older sedans that is a longer version of the normal procedure. On the newer cars it is a dedicated reset that takes more time and tooling. That is the $100 to $200 add-on, and it is the reason a spare today is cheaper than a replacement later. Our piece on why you should program a second key now does the arithmetic.

What Pushes an IS or GS Quote Up or Down

Whether a working fob exists

The largest factor. One working fob means a direct registration, usually under an hour. None means the reset described above.

The fob's part number and features

IS and GS fobs differ by generation, button count, and on some years by trim and option package. The replacement must match. We identify it from the FCC ID printed inside your existing fob, the radio-equipment identifier the Federal Communications Commission requires on every transmitter sold here (fcc.gov), or from the VIN when no fob remains. A fob with the wrong part number may unlock the doors and never start the car.

Who supplies the fob

Bring a correct, brand-new fob and we quote registration only, which is the lowest line on the sheet. Confirm the part number with us before buying; a fob returned to an online seller is money and days lost.

The 12-volt battery, especially on the hybrids

The GS450h and the older hybrid sedans run the same Smart Access system as their gas siblings, but their 12-volt battery is small and the car is sensitive to low voltage during a registration session. Many "my Lexus suddenly stopped seeing the fob" calls on hybrids trace to a weak 12-volt battery rather than the key. We test it first; it is a cheaper fix. On any IS or GS that has sat for weeks at DFW Airport long-term parking, tell us before we arrive, and read our guide to a car that will not start after long-term airport parking for why a tired battery and a dead fob look identical.

A fault that is not the fob

A Lexus that will not see a known-good fob may have a failing door antenna, a smart key module fault, or a module left confused by a low-voltage event. On-site diagnosis runs $75 to $145, and any module work beyond a fob gets an exact quote after we have the VIN and the module identified. Our overview of Lexus smart key and Smart Access immobilizer work covers the system side, and our guide to push-to-start not working with no fob detected walks through the detection faults.

"An IS350 with one working fob is one of my cleanest jobs: fob on the van, register it, test the doors and the start button, done. The same car with no fob is a reset, and on a 2021 or newer I want a power supply on it and signal in the garage before I promise a time. Same price band. Different hour." — a senior technician on our Irving crew

Three Lexus Quotes, Worked Through

Composites of the calls we take most often from Farmers Branch and Irving, with figures from the bands above.

A 2009 IS250 in Farmers Branch, one working fob, wants a spare. Second-generation IS, mature procedure. A second Smart Access fob registered in the driveway falls in the $300 to $500 band, typically done in well under an hour.

A 2015 GS350 in Las Colinas, lost the only fob. Fourth-generation GS, no working key. The fob falls in the $300 to $500 band plus the $100 to $200 all-keys-lost reset. We confirm the VIN and ownership documents, ask where the car is parked, and arrive with the fob on the van. No tow.

A 2023 IS300 in Irving, one fob, second driver in the household. Newest security generation. A second fob falls in the $300 to $500 band. We connect a power supply, confirm the authenticated session, register the fob, and test both fobs independently before leaving.

Dealer Versus Mobile Locksmith for a Lexus Sedan

A Lexus dealer can replace any IS or GS fob, and if the car is under warranty with a Smart Access fault, the dealer is the right first stop, because the repair may cost nothing. NHTSA's recall lookup by VIN tells you whether an open campaign applies (nhtsa.gov).

For an ordinary lost or spare fob, the difference is logistics. The dealer needs the car at the dealership, which means a flatbed when no fob works, and the American Automobile Association's roadside figures put a Dallas-Fort Worth tow well into three figures before any key is made (aaa.com). The fob may need to be ordered and the service schedule decides the day. A mobile locksmith comes to the sedan, carries the common IS and GS fobs, and finishes where the car sits. For the full comparison, see car key programming near you: mobile versus dealer.

The Rest of the Lexus Family in Farmers Branch and Irving

If the household also has a Lexus SUV, the pricing logic here carries over to the RX and ES, which we cover in our RX and ES all-keys-lost guide. The body-on-frame GX and LX are a different story on the ignition side, and our GX and LX ignition repair guide covers that. For the broader Farmers Branch picture across all makes, our car key replacement cost in Farmers Branch page lays out the bands, and the Farmers Branch service area page lists the neighborhoods we cover.

What to Have Ready Before You Call

Model year and model. It settles the generation and the fob.
The VIN. Base of the windshield, driver's side, and on your registration.
Whether a working fob exists. The largest factor in the price.
Ownership documents. Title or registration in your name plus a matching photo ID. We verify ownership on every key job, which the Associated Locksmiths of America treats as a baseline professional standard (aloa.org). Texas licenses locksmiths through the Department of Public Safety's Private Security Program, and we operate under it.
Where the car is parked. Driveway, surface lot, or garage, and whether a phone gets signal there.

Frequently Asked Questions

How much does a Lexus IS or GS smart key cost in Farmers Branch or Irving in 2026?

As of October 2026, a Smart Access fob registered with a working key present runs $300 to $500, with mobile service during business hours included. If every fob is gone, the all-keys-lost reset adds roughly $100 to $200. We confirm the exact price against your VIN before dispatch.

Can you replace a Lexus key if all my fobs are lost?

Yes. With no working fob, the smart key control module has to be reset so it will accept a new registration, which takes longer and costs roughly $100 to $200 more than adding a spare. We bring the tooling to your location, so the car does not need to be towed to a dealer.

Does a used Lexus fob from an online listing work?

Usually not. Lexus fobs stay tied to the vehicle they were registered to, so a secondhand fob generally cannot be registered to your car. A brand-new fob with the correct part number works, and if you supply one we quote registration only. Send us the listing first and we will tell you whether it matches.

Is a GS450h hybrid key more expensive than a GS350 key?

No. The hybrid uses the same Smart Access fob as the gas model of the same generation, so the band is the same, $300 to $500. The procedure differs only in how we confirm the key works, by checking that the car enters Ready mode, and in our testing the small 12-volt battery first, since a weak one causes many false fob complaints on hybrids.

How long does Lexus smart key programming take?

Adding a spare with a working fob present typically takes 30 to 45 minutes on-site. An all-keys-lost reset often takes an hour or more, longer on the newest IS because of the authenticated session and the voltage and signal checks that go with it.

Do all Lexus IS and GS models have push-button start?

Yes, for the sedans sold in the United States from the 2006 model year on. Both adopted the Smart Access system across every trim with the generations introduced that year, so every IS and GS key job here is a smart key job rather than a blade transponder key.

Is it cheaper to use a locksmith or the Lexus dealer for a key?

For a lost or spare fob, a mobile locksmith is usually cheaper once you count the tow the dealer path requires when no fob works, and usually faster, since the work happens where the car sits. The dealer is the better choice when the car is under warranty with a Smart Access fault that may be covered.

Get a Lexus IS or GS Quote in Farmers Branch or Irving

Text or call 817-842-1751 with your year, model, and whether you have a working fob. We quote the full price before we roll, and we cover Farmers Branch, Irving, Las Colinas, Carrollton, Coppell, Grand Prairie, and the surrounding Dallas-Fort Worth cities. Our Lexus brand page covers the rest of the lineup, and our key fob programming service page covers what we bring to every call.

References

U.S. National Highway Traffic Safety Administration, theft prevention standard and recall lookup by VIN (nhtsa.gov)
Insurance Institute for Highway Safety, Highway Loss Data Institute theft loss reports by make and model (iihs.org)
National Automotive Service Task Force, Vehicle Security Professional registry (nastf.org)
Associated Locksmiths of America, professional standards for automotive locksmiths (aloa.org)
Federal Trade Commission, consumer guidance on auto repair estimates (ftc.gov)
Federal Communications Commission, equipment authorization and FCC ID lookup (fcc.gov)
American Automobile Association, roadside assistance and towing cost data (aaa.com)
SAE International, standards for vehicle anti-theft and keyless systems (sae.org)
Texas Department of Public Safety, Private Security Program licensing for locksmiths