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How Much Is a Replacement Mercedes Car Key?
A replacement Mercedes key runs from £250 to £600 on mainstream models, and £400 to £800 or more on AMG, EQ and G Class cars. The year decides the route, because key authorisation moved onto Mercedes own servers from around 2015. Mercedes calls the system the Fahrberechtigungssystem, its drive authorisation system, and the generation your car carries is the fact that settles who does the work and what it costs. On FBS3, roughly the 2004 to 2014 era, a qualified independent generates and authorises a key at the car. On FBS4 the key data is pulled from the factory through the manufacturer diagnostic platform, Xentry, with factory level authorisation, so the key cannot be produced locally and the job runs through a franchised dealer. The boundary sits at around 2015 and it moves by model line.
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What a Mercedes key costs, by model
These are finished job figures from a published United Kingdom price list rather than the price of a fob on its own, and each upper figure is open ended.
Read your own row against the generation table in the next section, because the figure and the route are decided by two different things.
| Model | Price band for the finished job |
|---|---|
| A Class and B Class | £290 to £550 or more |
| CLA and GLA | £300 to £580 or more |
| C Class | £310 to £570 or more |
| GLB | £310 to £600 or more |
| E Class, CLS and V Class | £320 to £600 or more |
| GLC | £320 to £620 or more |
| SLC | £330 to £600 or more |
| GLE | £330 to £650 or more |
| GLS | £340 to £670 or more |
| S Class and SL | £350 to £650 or more |
| Sprinter | £300 to £550 or more |
| AMG GT | £400 to £750 or more |
| EQC | £400 to £750 or more |
| EQS | £450 to £800 or more |
| G Class | £550 to £900 or more |
Completed work logged on a United Kingdom jobs platform puts the Mercedes brand range at £195 to £530, a figure that includes simpler spare key work on older cars. The two sets describe different jobs, so neither is an average of the other.
Where the 2015 line falls, model line by model line
Two rows in this table are the reason no page gives a clean cutoff year. The S Class crossed to FBS4 in 2014, before the boundary, and the E Class stayed on FBS3 into 2016, after it.
| Model line | Generation | System |
|---|---|---|
| C Class | W204, 2008 to 2014 | FBS3 |
| C Class | W205, 2015 onward | FBS4 |
| E Class | W212, 2010 to 2016 | FBS3 |
| E Class | W213, 2017 onward | FBS4 |
| S Class | W221, through 2013 | FBS3 |
| S Class | W222, 2014 onward | FBS4 |
| GLK and GLC | X204 GLK | FBS3 |
| GLK and GLC | X253 GLC, 2016 onward | FBS4 |
| ML and GLE | Early W166 builds | FBS3 |
| ML and GLE | Later W166 and newer GLE | FBS4 |
So 2015 is a guide rather than a hard line, and the vehicle identification number settles it. The physical design of the fob does not, which is where owners go wrong when they try to tell from the key in their hand.
What an independent does, and where the limit falls
On an FBS3 car the key is coded locally, at the vehicle, which is why independent Mercedes key work is scoped to supported models up to around 2015, with the exact year varying by model line.
On an FBS4 car the authorisation lives on Mercedes servers in Germany rather than in the car. New key data is pulled from the factory through a two way encrypted exchange on the manufacturer diagnostic platform, and that access sits at dealer level. The limit is authorisation rather than skill or equipment, so no amount of tooling in a van changes it.
The honest statement, and the one this page holds to throughout, is that an FBS4 key cannot be produced at the car and comes through the manufacturer.
Keyless Go, and the quote to walk away from
One verdict here, because it is the question sitting behind the price. On an FBS4 car with Keyless Go the key is ordered through Mercedes and authorised by a franchised dealer. There is no roadside independent version of that job, and a quote offering one at the kerb for the price of a mainstream key is pricing work that cannot be finished.
On an earlier Keyless Go car the independent route is open and the model bands in the first table apply. Give the vehicle identification number when you ask for a price and the answer stops being a guess, because the number resolves the generation before anyone travels.
Why a Mercedes key costs more than a key for another make
Because it is not a blank with a chip in it. The fob, the electronic ignition switch, the engine control unit and the electronic steering lock each verify one another, and every part is paired to that car.
FBS4 added multi layer encryption to that arrangement and moved the authorisation off the vehicle, and it also restricted module replacement, where the earlier system allowed modules to be adapted. A key that has to be released by the factory and confirmed through an encrypted exchange costs more than a key coded at the kerb, and that single change explains the gap between a 2012 C Class and a 2018 one.
What the dealer route needs from you
The key is ordered against the vehicle rather than taken off a shelf, and it is released to the owner or an authorised person on proof of ownership and identification. Activation is a separate step from supply and it needs access to the car, either at the dealer or at the vehicle, which carries a charge of its own. That is why the dealer route runs across days where the independent route runs across one visit.
- The vehicle identification number, which settles FBS3 against FBS4 before anyone quotes.
- The registration, with the model line and the year.
- The V5C, which shows the registered keeper. On a financed, leased or company car the keeper and the legal owner differ and the owner authorises the work.
- Photographic identification such as a driving licence or a passport.
- The number of keys in existence and where each one is, because the key count changes the procedure.
- A replacement V5C at £25 where yours is missing, allowing 5 to 7 working days for it to arrive.
Who Wrote This
Darius is the owner of Herts Car Keys and the locksmith on every job. He has six years in the trade and has completed over 7,000 car key and lockout jobs.
He is approved under the SERMI scheme, DBS checked and fully insured, and every key he supplies carries a 12 month warranty.
Car Keys Made at Your Vehicle
Call Darius with the registration and the model year.
Frequently Asked Questions
Call 07308 888825How much is a replacement Mercedes car key on average?
Mainstream models run £250 to £600 and the AMG, EQ and G Class keys run £400 to £800 or more. No single average is worth quoting, because published averages for car keys across all makes range from about £240 to about £340 and measure different things. Price it against your own model and year.
Why are Mercedes replacement keys so expensive?
Because the key is one member of a paired set. The fob, the electronic ignition switch, the engine control unit and the electronic steering lock each verify one another, and from FBS4 onward the authorisation comes from Mercedes own servers rather than from the car. A key released by the factory costs more than a key coded at the kerb.
Can I buy a Mercedes replacement key online?
A fob bought online is a part. It still has to be cut and authorised to your car, and on an FBS4 vehicle that authorisation comes only through the manufacturer, so the online fob shortens nothing. On an FBS3 car an independent supplies and authorises the key as one job, which is the cleaner route.
How much is a replacement Mercedes car key with Keyless Go?
On a car from around 2015 onward it is a dealer job, priced at the dealer rate for that model, with the bands in the first table as the starting point. On an earlier Keyless Go car the independent route is open and the same model bands apply. The vehicle identification number decides which of the two you are in. Pairing the Keyless Go side of a fob to the vehicle is remote key programming.
Do insurance policies cover the cost of a Mercedes replacement key?
Only where the policy carries key cover. The limit, the excess and the effect on a no claims bonus are set by the individual policy, and one published policy pays nothing on keys lost for less than three days and nothing inside 48 hours of the cover starting. Check your own schedule rather than assuming.
How long does it take to get a new Mercedes key?
On an FBS3 car the key is cut and coded at the vehicle in one visit. On an FBS4 car the key is ordered from the factory and then activated with access to the car, so it runs across days rather than hours. Ask for the lead time at the point of quoting. The timings for a key cut and authorised at the vehicle sit under car key replacement.
How do I tell whether my Mercedes is FBS3 or FBS4?
By the vehicle identification number rather than by the key. The design of the fob does not reliably indicate which system the car carries, and the model year boundary moves by model line, with the S Class crossing in 2014 and the E Class staying on the earlier system into 2016. Quote the number and the answer arrives before anyone attends.