Mercedes C-Class Radio Code: Unlock Your Audio 10 or Audio 20

The Mercedes-Benz C-Class W203 (2000–2007) is a popular used car in the UK. The original head unit — usually an Audio 10 CD (Alpine) or Audio 20 — locks after a power interruption and displays CODE. This guide explains how to retrieve your Mercedes C-Class radio code.

Head Unit Types in the W203

• Audio 10 CD (Alpine): The standard single-disc CD radio
• Audio 20 (Becker): The premium radio with display and CD changer
• COMAND (Becker): The navigation system with built-in radio

Finding the Serial Number

The method varies depending on which unit is fitted in your W203:

Audio 10 CD (Alpine)

1. Switch the radio on — the display shows CODE.
2. Hold buttons 1 and 2 simultaneously.
3. The serial number (starts with A or BE) appears on the display.

Audio 20 / COMAND (Becker)

1. The serial number is on the label on the rear of the unit.
2. Remove the radio using Mercedes DIN release keys.
3. Note the Becker serial number (starts with BE followed by 4 digits).

Retrieving the Stereo Unlock Code

1. Go to RadioCodeLookup.com/brands/mercedes.
2. Enter the serial number.
3. Receive your Mercedes C-Class radio code.
4. Enter the five-digit code using the preset buttons.

Important: Mercedes Codes Are Five Digits

Unlike most other makes, Mercedes stereo unlock codes are five digits long. Make sure you enter all five digits correctly.

Frequently Asked Questions

My W203 Audio 10 shows WAIT. How long must I wait?

With a WAIT message, leave the ignition on for at least one hour. The radio counts down internally and returns to CODE mode afterwards.

Can I retrieve the W203 radio code using the VIN (chassis number)?

At Mercedes, it is sometimes possible to look up the code via the VIN, but only through an official dealer. Via RadioCodeLookup.com you use the radio's serial number.

My COMAND system is asking for a code after a software update. Is that normal?

Yes. Some updates reset the security system. Simply re-enter your Mercedes C-Class radio code.