We recently reviewed 27 credit cards that offer same-day use. These cards allow you to use your account even before you receive the physical card. Until the card arrives, you’re limited to card-not-present (CNP) purchases, either over the phone or online. This is usually implemented using virtual account numbers. A virtual account number is cooked up by the credit card issuer and bears no relationship to your actual number. Most are one-time use only, but some can be reused. Typically, you go online to a merchant and enter the virtual card number as you would the actual number. Single-use virtual cards limit the damage fraudsters can inflict if they happen to steal the virtual number. Some issuers offer virtual account numbers on all their cards. For example, you can use the Eno feature to generate virtual Capital One card numbers. Another issuer of virtual cards is Citibank, which offers this service on select Citi cards. In addition, American Express offers its vPayment virtual card service, but only on business cards. Bank of America recently discontinued its ShopSafe program that provided virtual cards.