Most of the IDs, 53,000, can be linked to a mobile phone, while email addresses are linked to 30,000 bank accounts.

The tax number or tax identification mark is slightly less popular, but it also is attached to more than 10,000 invoices. However, the majority of transactions have not followed through with registration.

According to the MNB's data, only 50,000 have been initiated with a secondary identifier so far, with a total value of HUF 3 billion. An average transaction was nearly HUF 60,000.