# Anti-Theft PIN
Canonical URL: https://mbretrofit.it/guides/professional/anti-theft-pin
Description: Mercedes head unit activation PIN after a replacement. Submit the command serial and we return the unlock PIN so the unit boots.


## Looking for an anti-theft PIN? Look no further.

When a head unit is installed in a different car, it locks itself and asks for an **anti-theft PIN** before it will boot. Without it the unit stays stuck on the activation screen.

We look up the PIN for you in official database sources. You enter it with **DTS Monaco** and the unit boots.

## What we need

* **Command Serial Number**: the 14-character identifier read from the installed head unit.
* **Original VIN** (optional): the VIN the unit was originally paired to. Speeds things up when available.

Submit both on the [Anti-Theft PIN page](/app/professional/anti-theft-pin). You get the PIN by email during EU business hours.

## How to find the command serial number

Two options, in order of preference:

1. **Read it with DTS Monaco.** Connect an OBD diagnostic device, open DTS Monaco, and pull the command serial directly from the head unit. Most reliable source.
2. **Read it off the sticker.** If the unit is out of the car, the serial is on a sticker on the top of the head unit next to the part number.

### Serial format (important)

Ensure the serial you submit meets the following criteria:

* The serial must be **exactly 14 characters**.
* It begins with one of: `AL`, `GA`, `HB`, `HM`, `ME`, `PA`, `VT`, or `CO`.
* If your sticker starts with `BE`, replace it with `HB`. Our form does this automatically.

If the sticker is unreadable or doesn't match the format, read the serial directly from the head unit with a diagnostic device.

## How to enter the PIN

Open **DTS Monaco**, connect to the head unit, navigate to the anti-theft / activation routine, and enter the PIN we sent you. The unit boots.

If you're stuck, reply to the delivery email and we'll walk you through it.

## Keep in mind

* You're paying us to search for a match in official database sources. The PIN is **looked up, not calculated**.
* If the head unit has been reported stolen, a PIN cannot be obtained.
* If no match is found, the credit goes back to your balance and you can reuse it for another search (corrected serial, different unit).
* Once a PIN is delivered, a refund isn't available.

## Turnaround

During EU business hours, typically the same day.

## Pricing

€50 per PIN, or one anti-theft PIN credit from a bulk pack.