Well, as of 3/1/2023 you'll be entitled to a refund of the remaining calling credit of the number you want to transfer to another operator. A few important notes:

You can request the refund only if you immediately transfer the number of the prepaid card to another operator. If you terminate the number, no calling credit will be refunded.
The refund can only be requested for calling credit purchased via a top-up. A free bundle of mobile data, e.g. a bundle from a Viking Clan, will not be refunded.
Keep in mind we will deduct the amount of € 5 for administration costs from the remaining calling credit. This means that amounts lower than this will not be refunded.
You need to request your refund within 1 month after the transfer to your new operator.
The refund will be done in the same manner as the calling credit was initially purchased: via Bancontact, MasterCard, VISA, Paypal or direct debit.
After approval of your request by Mobile Vikings the refund will take place within 2 weeks after your request.

As of 3/1/2023, you'll be able to request your refund here. Please provide as much information as possible, so our helpdesk can have a look at your options as soon as possible.

Prepaid SIM card