Find your Link ECU serial number
There are a number of ways to find the serial number of your Link ECU.
Plug-in ECUs
Link Plug-in ECUs have a small sticker with a QR code and serial number on the board itself.
In PC Link
If you are a PC Link user, hook up your ECU, and in the software select Help > ECU Information. The serial number will be in the pop-up window.
Ask your Link Reseller
Your Reseller might have a record of your serial number, and more likely if they tuned your ECU.