Great Britain Rail is an online booking service for train travel across the British National Rail network. It helps passengers compare ticket options and book journeys with train operating companies, offering an alternative to buying tickets at station offices or machines. The site explains key ticket types, including flexible Anytime fares, Off-Peak and Advance tickets, area-based Rover and Ranger tickets, travel passes, and discounted fares available with concession cards such as railcards.

A central feature is its split-ticketing service. When customers search for a journey, the booking system identifies available options, including combinations of tickets that may cost less while allowing passengers to travel on the same train. The site reports average savings of £21.60 per journey through split tickets. Great Britain Rail also provides information on refunds and amendments, ticket prices, timetables, stations, operators, and service disruptions, alongside passenger guidance and an app for quick access. Its travel resources also link to hotel reservations, coach travel, flights, ferries, and holiday options, including rail, cruise, and coach holidays.