Will my NatWest Debit card work on the train to buy tickets ?

A question about : Will my NatWest Debit card work on the train to buy tickets ?

I have just opened a NatWest current account, and I am wondering if I can use the Debit Card that came with it on the train, as I know some cards you cant and I don't really want the embarrassment of it getting declined. I know it works in the ticket machine at the station, but sometimes the machine is out of service (Small station with one machine) but I am just not sure about on the train, and I don't want to get into trouble by not having a ticket.

My friend has a NatWest debit card but hers is totally different from mines, hers is purple and has the NatWest logo in the centre of the card and the words Visa Debit in the top left hand side and the little contactless symbol at the middle right hand side. Mines is Purple, but only has the Words NatWest at the Top left, no Logo in the middle and Visa Debit at the Top Right hand side and the Contactless symbol in the middle.

Best answers:

• No it won't work regrettably.
  If your card starts with 4751 27, 4751 28, 4757 54 and 4757 55.
• I believe these are not accepted for on train purchases as they required the bank balance to be confirmed online each time a transaction is made, the on train machines cannot do this hence the cards are not accepted.
  I don't think the station machines can either for that matter.