The Visitor Oyster card let you travel on buses, subway, trains and Dockland Light Railway.
How it works?
The Oyster is a scalar card, it doesn't expire and it's not nominative. You can buy it with a pre-loaded credit from £15 to 40£, plus 5£ issue.
Everytime you take a public transport, the Card automatically remove the journey price, which is discounted if compared with the single ticket's fare. If you travel, the credit will be deducted, if you don't travel it will remain the same. The Oyster doesn't expire but it's credit will be deducted little by little when you use it. When the credit ends, you need to recharge it.
London is divided by zones that are base for the rail service fares (includes underground & tram), these zones are concentric rings. The zones 1-2 cover the urban area, while the zones 3-6 correspond to the "Big London" and they include the London City Airport (zone 3) and Heathrow Airport (zone 6).
When you travel, the Oyster "knows" the journey you have made and it deducts you the relative amount. The most important thing is that Visitor Oyster card offers daily capping. This means you can travel as much as you like in a single day and the amount you pay for your travel is limited (or capped). The prices for daily capping are different from zone to zone. If you reach the capped amount, the next journeys are free and unlimited.
Let's see prices and how they change zone by zone:
Let's do an example: you have bought an Oyster charged with £25 (+ £5 emission costs). You take the public transports for the first time in a weekday morning, before 9.30 (peak) and you remain within 1-2 zones, the Oyster deducts you £ 2,90. Than you take another journey, after 9.30 (of-peak), it will deduct you £2.40. Tot £ 5,30. If you take another journey, it will deduct you only £1,50 because you will have reached the maximum daily charge, which is £6.80 for the 1-2 zones. The next journey you will take in that day will be free and unlimited.
So if you stay within 1-2 zone, taking advantage of the £ 6,80 daily cap, you can travel freely and in an unlimited way for 3 days.
you can get refund of the remaining credit (maximum £ 10) from a tube station machine, placing the card close to the reader and pushing the "Oyster refund" button. The card will be nullify and the machine will give you back cash credit.
How to use the Visitor Oyster card
Everytime you have to take the tube, the train or a bus, you have to "tap" you Oyster on the yellow readers. That's how they are made:
On tubes and train you have to tap the card again when you exit, so keep it at hand. On the buses you need to tep the card only when you get on, not when you get off.
When you tap the card on the reader, an acoustic sound warns you of the successful check-in and your credit appears on the display. Never tap twice. If you have any doubts (the gate does not open, you can't pass in time) immediately contact the subway staff, who's always at the turnstiles, they'll be happy to help you and you will avoid additional charges.