I just opened up a new bank account in natwest and nationwide and received my debit card in the post along with my pin. I was just wondering how do I put money into my account with my debit card, over the counter at a natwest or nationwide branch.

I don't bank at that bank, but at all the other banks I've been to, you just go up to the atm, they have a slot for you atm card. You insert your card, enter your pin, and then hre's options on the screen. To put money into your account you would want to choose "deposit" and from there it should have instructions to walk you through it (where to put your money in, which way to turn the envelope that's usually provided, etc.). Or you can always go inside and see a bank teller.