International mobile remittance
International mobile remittance (also known as international mobile airtime recharge / international top-up / top-up credit) is a remittance transfer service which allows a person in one country to securely and electronically transfer or top-up mobile credit to another mobile belonging to a family member or friend abroad. The top-up can happen through various payment mechanisms.
Source: Wikipedia — International mobile remittance (CC BY-SA 4.0)