Millions of Londoners risk not being able to get a refund if their Oyster card is lost or stolen as they haven't registered it to their online account.

Approximately 6.39 million unregistered Oyster cards were used on the Transport for London (TfL) network in the eight weeks leading up to 21 March, a MoneySavingExpert Freedom of Information request found.

And if these cards were lost or stolen, their owners wouldn't be able to transfer their balance or travelcard on to a new Oyster card, as they would have no way of proving that they owned the card.

This issue will only affect those buying an Oyster card or topping it up at a station, rather than online, as to order or add funds to an Oyster card online you would have to register it.

Around 70% of Oyster cards are not registered. The vast majority of these will have been bought at self-service machines.

See Oyster card refunds to find out how to get money back on your Oyster.

Why should I register my Oyster card?

There are various benefits to registering your Oyster card. Here are some of the best MoneySaving ones:

  • If your Oyster card is lost or stolen, you can transfer credit onto a new card – you just need to notify TfL and it will transfer your credit onto a new Oyster card and prevent anyone from using the old card. You can transfer both your balance and any existing travelcard, as long as there's AT LEAST five days remaining on the travelcard. See the following links for the full process: lost Oyster card and stolen Oyster card.
  • See your incomplete journeys and get refunds for them – when you use pay-as-you-go you must touch in and out for all tube, Docklands Light Railway, London Overground, TfL Rail and National Rail journeys. If you don't, TfL doesn't know where you've travelled and so could charge you a maximum fare of £8. If you are wrongly charged the maximum fare you can get a refund on the My Oyster Cards page.
  • Set up an auto top-up or top-up online – you can set a recurring top-up or auto renewal of your travel card, or top-up online, instead of waiting at the station.

How do I register my Oyster card?

The process for registering your Oyster card is simple and free.

First of all, you need to create an Oyster online account.

To do this, you'll have to enter the number on the back of your Oyster card, and recall your last journey made with the card, before filling in your personal details.

This card will now be registered, and you can register more cards on your My Oyster Cards page using the same process.

What if I use my contactless bank card on the TfL network?

Figures from last year show that 40% of all pay-as-you-go journeys on the TfL network were made using contactless, rather than an Oyster card or train ticket.

If you use your contactless bank card on the TfL network, you can't get travelcards and can only pay as you go. If you were to lose your bank card, it would be your bank you would contact, rather than TfL.

You can still register your card on your Oyster Online account. You won't get as many features as you do when registering your Oyster, but you can see an in-depth payment history and claim easily if your tube journey is delayed or incomplete.