The payment tag is a safe alternative to cash or a traditional card. Payment tags use technology called radio frequency identification, or RFID, to securely send your account information to special readers at checkout. After tapping your tag, your purchase details are processed through the MasterCard secure network for approval. It’s that simple. When you make a purchase, it never leaves your hand No personal or account information, such as account number, name, or signature, is displayed You’re protected by Citi’s promise of $0 liability on unauthorized charges