(19 Jul 2014, 4:57 pm)Andreos Constantopolous wrote The Key Cards are free, but certainly don't offer the level of fare discounts seen elsewhere - like London.
I have an Oyster Card. I've actually used it more than my Key Card over the last few years through my visits to The National Archives. I was persuaded to obtain one after learning about how much I could save. The card was posted to my home address without any problems or restrictions.
Oyster Cards do cost £5. However it must be said that this is a deposit not a charge. If I wanted my £5 back I could quite simply return the card.