To save your money and you choose to stay in central London, the first day of travel will be from Heathrow airport if you stay for 4-7 days. However, we recommend that you buy a weekly card for zones 1-3 and only top up the extra money on the card just for travelling from the airport (which is in zone 6) to your hotel in central London. After that you can travel in central London with your Oyster card with unlimited usage (zones 1-3) since most of the London attractions are in Zone 1.

When you walk into the underground station at Heathrow, you will see ticket machines where you can purchase tickets with English Pounds (Sterling) or with your credit card. Just look through options on the machines displaying 'new card' then just following the instructions. There are TfL staff who can help you too.
For more details about prices, services and much more, visit Transport for London's website or goto www.tfl.gov.uk and for network maps visit https://tfl.gov.uk/maps

In addition, you can get around London by hiring bikes or goto https://tfl.gov.uk/modes/cycling/santander-cycles. Once known as Boris bikes as Boris Johnson introduced them to London as a way to help reduce traffic and pollution. They are cheap to hire from as little as £3.00 for up to 30 minutes use within a 24 hour period. If you time it correctly, you could ride all day for £3.00 providing you dock your bike within 30 minutes each time and of course first find a free docking station to dock the bike within the 24 hours. Charging rules apply so be very careful and read the instructions. There's an app you can download too. One useful part of the app includes notifying TfL if the docking station you have arrived at is full. Just enter 'No docking point free' at the terminal and follow the on-screen directions to get an extra 15 minutes. To find out how it works goto https://tfl.gov.uk/modes/cycling/santander-cycles/how-it-work.