Capping is a feature of the pay-as-you-go Oyster cards which allows you to make a number of journeys in a single day but limits the amount you pay for your travel.
Each time you make a journey, you are charged a fare. Once the total cost of all your fares reaches a certain amount you won’t have to pay for any more journeys for the rest of the day. This is called a cap.
If you make a lot of rail journeys or a mixture of rail, bus and tram journeys in one day within Zones 1-9, pay as you go with daily capping is better value than buying a Day Travelcard. If you make a lot of bus and tram journeys, pay as you go with daily capping is better value than buying a One Day Bus & Tram Pass.
To benefit from capping, you must touch in and out* on every journey using the same Oyster card.
*Note: do not touch out on buses, trams, or Thames clippers.