A rechargeable calling card or a recharge card is a type of telephone card that the user can "recharge" or "top up" by adding money when the balance gets below a nominated amount. In reality, the rechargeable calling card is a specialised form of a prepaid or debit account.
To use the phone card, the user would call an access number (which is usually a toll-free telephone number), enter the "card number" (also called the PIN) and then dial the desired telephone number. The user could add value to the card at the same time as making a call. When travelling, the user has a list of access numbers for various countries, enabling them to call from any phone in most countries and be able to top-up the card.
The so-called rechargeable calling card is merely a marketing device, but it is convenient to many users because it is a durable credit card size card. In reality, the system works by a user being provided with a unique "card ID" (the PIN). After transferring funds to the card company, the ID can be provided electronically by email, by SMS, over the internet, a coupon printed by a cash register at a store, or any other way. Also, as the card balance is actually recorded on the card company's database, topping up can be effected in any manner that funds can be transferred to the company.