Travelling around London with children can be surprisingly confusing. One journey might involve South Western Railway, the Tube, a bus, the Elizabeth line or London Overground, and the child fare rules are not always the same. Here are five useful things to know before you travel.

1. Children under 5 usually travel free

Children under 5 travel free on most trains, including South Western Railway. They also travel free on Transport for London services such as buses, the Tube, DLR, London Overground and the Elizabeth line. They do not usually need their own ticket, although on busy National Rail trains they may not always be guaranteed a separate seat.

2. Children aged 5 to 15 usually pay a child fare on South Western Railway

On South Western Railway and most National Rail services, children aged 5 to 15 usually need a child ticket. This is normally around half the price of an adult fare. Once a child turns 16, they usually need an adult ticket, although a 16–17 Saver can help reduce the cost.

3. London transport has more generous rules for younger children

Transport for London has different rules from normal National Rail journeys. Children under 11 can often travel free on London buses, trams, the Tube, DLR, London Overground and the Elizabeth line when travelling with a fare-paying adult. In many cases, up to four children under 11 can travel free with one adult.

4. Children aged 11 to 15 may need a Zip Oyster photocard

Children aged 11 to 15 do not automatically get the same free travel as younger children. A Zip Oyster photocard can give them free or discounted travel on London transport. This is especially useful for families who travel in London regularly, as it can make a big difference to the cost.

5. The important thing is whether your journey is TfL or National Rail

This is the part that catches many people out. A 9-year-old might travel free on the Tube or a London bus, but may still need a child ticket on a South Western Railway or other National Rail journey. As a simple rule, under 11s often travel free on TfL services in London, while children aged 5 to 15 usually need a child ticket on National Rail.

The best advice is to check the type of journey before you travel. If you are using buses, the Tube, DLR, London Overground or the Elizabeth line, look at TfL’s child fare rules. If you are using South Western Railway or another National Rail service, check the child ticket rules when booking.

Knowing the difference can save money and avoid confusion at the ticket gates.