Proximus collaborators (moderators) on this public forum will certainly be able to inform you about it, however it couls take some time (a couple of hours or even a couple of days , depending on the number of messages to be handled)

Proximus will assign you a GSM phone number (format : 04wx yzkhdu) & a customer number

Based on the contract you did subscribe in the shop the monthly subscription fee will be paid via “european direct debit mandate” (SEPA) European direct debit - ECC Belgium

or otherwise you will be informed by Proximus via sms/e-mail/lettre on the amount to be paid before due date

How to pay your bill or payment statement? | Proximus

Detail bill info will become avaible via your My proximus account

How to register for MyProximus? | Proximus

Hi @Lucia Vimini could you please fill your profil with your mobile number and fill the field “Ticket” with the sim number (start with 2100.. ..) ?