Malformed Advertising ID Filter

Adjust applies the Malformed Advertising ID filter when device matching. It removes all installs with invalid advertising IDs from your dataset. You don’t need to activate this filter; it is automatically on for all clients.

An advertising ID is a string containing a fixed number of characters. Each character in the string has a given range of permitted values. Advertising IDs always follow the same format, so if some characters are missing or appear where they shouldn’t, the ID is invalid and therefore fraudulent. This is true even if that device has other valid identifiers available.

Growth solution:
The Fraud Prevention Suite is available as an Adjust Growth Solution. To get Fraud Prevention on your account, contact

View rejected traffic


  • Enabled global rejection callbacks 

To view your rejected Malformed Advertising ID traffic, you must have the Fraud Prevention Suite enabled and global rejection callbacks set up. With these conditions met, you can view your rejected traffic as shown below.

In reports

  • You can see data under a network-level link called untrusted devices::malformed advertising ID

In your raw data

  • The {activity_kind} placeholder returns the value rejected_install
  • The{rejection_reason} placeholder returns Malformed advertising id