Have a Amex card that rewards you with avios? Use it as a contactless when traveling in london and get an extra 10 avios for every £2 spent. One first has to save the offer to one's Amex card.
Receive 10 extra Avios for every £2 spent, valid until 6 November 2016.
Available when using your contactless Card to pay as you go on bus, Tube, tram, DLR, London Overground, TfL Rail, Emirates Air Line, Thames Clipper River Bus and most National Rail services in London during this promotional period.
Offer excludes travel on Heathrow Connect.
Up to a maximum of 1,000 Avios per Cardmember for the first 50,000 UK Cardmembers to save.
Payment is required in full on the American Express Card to which the offer is saved.
Offer only applies to spend made in Great British Pound (GBP) on the Card to which the offer is saved, including an American Express Card loaded into a mobile payment wallet.
Offer does not apply to spend on other Cards you might hold and is not valid for transactions made using Payment Aggregators including, but not limited to, PayPal.
An awarded credit may be reversed if qualifying transaction is refunded or cancelled.
Credit should appear on your billing statement within 5 days from qualifying spend but may take up to 90 days from 6 November 2016.
Can't find a link on either American express's website or TfL's website for this offer.
Only link I could find was: