[1] Travelcards can be purchased for a period of time varying from one day to a year, from Transport for London, National Rail and their agents.

Depending on where it is purchased, and the length of validity, a Travelcard is either printed on a paper ticket with a magnetic stripe or encoded onto an Oyster card, Transport for London's contactless electronic smart card, or an ITSO smartcard issued by a National Rail train operating company.

[2] The cost of a Travelcard is determined by the area it covers and, for this purpose, London is divided into a number of fare zones.

The introduction of the Travelcard caused an increase in patronage and reduced the number of tickets that needed to be purchased by passengers.

[5] In 1983, a third revision of fares was undertaken, and a new inter-modal Travelcard season ticket was launched covering five new numbered zones; representing an overall cut in prices of around 25%.

[5] The Capitalcard brand ended in January 1989 when the Travelcard gained validity on British Rail and DLR services.

[12] However, in October 2023, it was announced that due to a renegotiation on revenue sharing, one day Travelcards would be retained.

An outboundary day Travelcard can be used to make one outward journey from the origin station to the boundary of zone 6, then one return journey back to the origin on the same day, with unlimited travel allowed within the zones shown on the ticket.

In addition, Travelcards between Zone 1, 2 or 4 and Watford Junction, Zone 1 or 2 and Hertford East / Broxbourne, and Zone 1 or 2 and Shenfield are also available on Oyster cards, with a Travelcard for Hertford East / Broxbourne also including Watford Junction, and a Travelcard for Shenfield also including Watford Junction and Hertford East / Broxbourne as well.

A class action lawsuit has been filed against the train companies requesting a total of £93 million in compensation; the case has not yet been heard.

The historical Heathrow Connect service did not accept Travelcards at the airport either; they could be used on the rest of its route between Hayes & Harlington and Paddington, but when this route was replaced by TfL Rail and later the Elizabeth line, this restriction was dropped and Travelcards are now usable there.

The revenues from Travelcard sales are divided according to a scheme agreed by Transport for London and the Rail Delivery Group.

Ensuring that a statistically valid sample that will give a fair and accurate allocation presents a challenge.

The average mileage recorded on each mode is then calculated to give allocation factors of the Travelcard revenue to tube, bus and rail.