Where do I find the UID on my RFID card?

Where you find the UID depends on where your RFID card comes from. As an ASTAG charge customer, you receive an Excel list of all UIDs by email when you place an order, whereas on RFID cards you received from Depotcharge, the UID is printed on the back.

For your own RFID cards from other providers, the easiest way is to read the UID with an NFC reader app, for example "NFC Tools", which you can find in the common app stores for smartphones.

The UID is a technical string of characters that you enter in the Unique card identifier (UID) field without spaces. The Card number next to it, by contrast, you can choose freely.