When my new card arrived from NatWest it had the same details as one already listed on Amazon

I was Christmas shopping on Amazon and realised there was a payment card on my account that I had never seen or used before. I only have one card registered and, although it was due to expire at the end of the month, it was still valid.

Amazon told me the new card had been added to my account on 12 December, but couldn’t explain to me how.

I knew that my bank was due to send a new card to my mum and dad’s address and planned to collect it when I visited at Christmas. When it arrived, I asked my mum to open the letter on my behalf, and it turned out the last four digits and the expiry date matched the card on my Amazon account.

I rang my bank, NatWest, and it told me that I should speak to Visa. I rang Visa and was promptly redirected back to NatWest. Amazon was no help at all. I find it quite worrying that Amazon could get my new bank card details before I had them. IA, Southport

NatWest’s press office agrees that this is “odd” and Amazon’s has to do some digging. None of us, it seems, were aware of VAU – Visa Account Updater. This allows subscribing merchants to receive automatic updates to cardholder account information, including account numbers and expiry dates. It sounds ominous, but the idea is to save retailers – and customers – the hassle of recurring payments being declined when a registered card has expired. All companies that subscribe must adhere to the Payment Card Industry Security Standards to ensure the stored data is protected. Mastercard operates a similar scheme. It’s been around since 2006 and most major retailers who offer recurring payments by card use it. The reason so few of us know of it is because its existence is buried in the terms and conditions of the card issuer. If you want to opt out, you have to do it via your bank.

If you need help email Anna Tims at your.problems@observer.co.uk or write to Your Problems, The Observer, Kings Place, 90 York Way, London N1 9GU. Include an address and phone number.