Brilliant product. Kudos to Starling Bank. Although one whose compelling need is legalistic in nature.
Not sure how widely known it is that debit card and credit card are not transferable. According to payment card rules, you can’t authorize anyone to use your debit or credit card. Not even anyone in your family. Not even for a single use.
The only way for Y to use X’s card to shop in X’s behalf is, if the bank has issued another, transferable, linked card to X, which X can legally handover to Y. This is what Starling Bank has enabled.
This is one of those rules in banking that are widely broken but rarely called out. But rarely does not mean never, as some poor sods find out to their dismay. There was this recent case where a woman was unwell. She handed over her debit card to her husband to go to an ATM to withdraw cash. The currency notes got stuck, no money came out, but the account got debited. Woman sought refund from bank. Bank played back the CCTV feed, said cardholder is woman, but man was using card, so there’s illegal use of card, so bank is not liable for refund. The customer filed a lawsuit with consumer court but the court found for the bank.