The Viva card (specifically the Viva Viagem) is the primary rechargeable transport card for the Lisbon metropolitan area in Portugal. To use it, you must first purchase the physical green card for €0.50 at any Metro station vending machine or ticket office. You then "load" it with credit using one of three methods: a single ticket, a 24-hour pass, or "Zapping" (pre-loading a cash balance). To ride, you simply tap the card on the yellow or green circular readers at the entry gates for the Metro or train, and again at the exit gates to end your journey. On Carris buses and trams, you only need to tap once upon boarding at the reader located near the driver. If using the "Zapping" method, the fare is automatically deducted at a discounted rate compared to buying paper tickets on board. It is crucial to keep your receipt when you first buy or top up the card, as it serves as proof of purchase if the card’s magnetic chip fails—a common occurrence if kept near mobile phones.