You can find the 12-digit number of your A1 account:
• in the e-mail message sent by A1 (if you are registered to receive electronic bills);
• on your A1 account (electronic and printed);
• on the mobile application "My A1" in the "Accounts" section (from the "List of accounts" section, you need to click on the account for the corresponding month, which will take you to the "Account information" section);
• on the "My A1" web application in the "Accounts" section (in the column titled "Account number"); or
• by sending a free SMS message with any content from your phone number to the number 14500, during which you will receive a return message with information about the account number (this service is only valid for physical users of mobile lines).