Before turning to paid services, check these common locations where codes are often stored for free:

Try common factory default codes like 0000 or 1234 . Note: Be careful, as too many incorrect attempts can permanently lock some models. Using Free Radio Code Generators & Apps

Several mobile apps and online tools claim to provide free codes based on your unit's serial number.

If you bought the car used, the previous owner may have recorded the code.

Check the "Security" or "Stereo" section of your vehicle's handbook. Manufacturers often include a small card or a sticker with the 4-digit code.