A top-up card is a payment method used to add credit or funds to a prepaid account, typically used for mobile phone or internet services. However, there are various synonyms for top-up card which can be used interchangeably such as recharge card, refill card, top-up voucher or airtime card. Each of these synonyms is unique to the specific service for which they are used. For example, recharge card is commonly used when referring to top-up cards for mobile phones in India, while refill card is used in the United States. Regardless of which synonym is used, all of them serve the same purpose of adding credit or funds to a prepaid account.