“Top up” is a term used to describe the process of adding more credit or minutes to a prepaid phone plan. It allows the user to continue using their phone service after their initial credit has been used up. The credit can be added or “topped up” by purchasing a top-up card or voucher, or by using a credit or debit card online or through a mobile app. Some services also offer the possibility of automatic top-up when the balance reaches a certain level, or a set date. In most cases, the user will have to enter a code or use a scratch card to redeem the credit and add it to their account.