About Smart radio codes
The head units in the Fortwo and Roadster came from Grundig, which is well documented and is the one we can act on. Their codes were issued rather than calculated, and we hold the lists. What decides the answer is the serial on the label, not the badge on the nose — so the free check is the fastest way to find out where you stand, and it costs nothing.
How to find your Smart radio serial number
The serial isn’t shown on the screen: it is printed on a label on the radio itself. The serial tells us exactly which code your radio needs.
On the label
- Take the radio out.
- Take a photo of the label and copy the serial: 14 letters and numbers starting GR.
Take a photo of the label rather than copying it by hand: it’s easy to mix up 0 and O, or 1 and I.
Most radios slide out with a pair of radio removal keys (a few pounds from any car parts shop). Push them into the slots on the front until they click, then ease the radio forward. Some have screws to undo first.
What your serial looks like
-
GR1043V0100001Grundig14 letters and numbers starting GR Instant
Can’t find it or can’t read it? Send us a photo of the label: £9.99, with a full refund if we can’t find your code.
Which Smart radio do you have?
These are the radios Smart fitted we know about, and whether we can unlock them. Not sure which is yours? Type the serial in: the free check works it out for you.
Popular Smart models
We cover models including:
- Fortwo
- Forfour
- Roadster
Years: Mostly 1998–2014. The serial is what counts, as radios are often swapped between cars.
How to enter your Smart radio code
Once you have your code, key it in like this. Your order page shows the same steps next to your code.
Grundig
- Set each number with the numbered buttons, then confirm (this varies by radio).
If your Smart radio says LOCKED, WAIT or SAFE
Each wrong code makes the radio wait longer before the next try, and some radios lock for good after too many. Don’t guess: get the right code first, then follow the steps for your radio.
| Radio | What to do |
|---|---|
| Grundig | Each wrong try adds a longer wait. Keep the radio switched on while it counts down. |
What LOCKED, WAIT and SAFE mean, and how long to wait →
Why we use your radio’s serial, not your number plate
A radio code belongs to the radio, not the car. A dealer usually looks it up from the Smart’s number plate or VIN (the 17-character number in your logbook), which only works if the car still has the radio it left the factory with. Radios are often swapped under warranty, upgraded, or changed by a previous owner.
The serial number is printed on the radio itself, so the code we give you matches the radio in front of you. It is also how we can check it for free before you pay. Main dealers often charge £30–£130, and you usually have to book the car in.
What we can and can’t do
We can do
- Grundig-built units — looked up in our code lists
We can’t do (yet)
- Units matched to the car rather than code-locked
- Touchscreen and media systems in the later cars
We always tell you before you pay. Not sure? Send us a photo of the label.
Smart radio code questions
Where is the serial on a Smart radio?
On the label on the unit. These do not show it on screen, so the radio comes out on release keys.
Is a Smart radio the same as a Mercedes one?
Not usually. Smart went to Grundig for most of its units even though Mercedes leaned on Becker. The serial settles it — type it in and the free check reads it.
How much is a Smart radio code?
£9.99 per code. The free check comes first, so you only pay once we know we can do it, and you get your money back if the code doesn’t work.
How long does it take?
Most Smart codes appear on screen the moment you’ve paid, and we email you a copy. If yours has to be looked up by our team, we email it within 2 hours and tell you before you pay.
What if the code doesn’t work?
Check the serial first: 0 and O, or 1 and I, are easy to mix up. Still stuck? Tell us from your order page and we’ll put it right or refund you in full.
Updated September 2026
