I have recently started using oyster cards for first time. I have not registered my details but use it as "pay as you go" topping up.

In good faith I topped up my card to travel from one side of London to the other side. I was told that (although cards are to be used on buses and London Underground they can also be used at Overground stations which operate Oyster cards.

My destination was to an overground station which I know had oyster card machines. Therefore, I started my journey taking my cycle on an overground station to Euston. No problem to and from Euston. I then cycled across London a few miles to another overground station. This station accepted my oyster card, but when I got to my destination the machine did not accept my card. I got an immediate fine of 20 pounds for not travelling with a valid card.

They told me that this particular line was run by a different train company and therefore had different rules. I tried to plead my ignorance but they would not accept it, no matter how convincing my argument.

They also told me that generally Overground stations which also run underground trains will accept my oyster but stations that only run overground and not underground do not. I find it hard to understand why they then have oyster card machines if they will not accept my card.

Anyway, my advice to everybody (in case you get caught out like me) is to check before you start whether all the stations you are using accept oyster cards. If any station doesn't then it is best to only use a normal travel card and not an oyster.