Depending on how many pay-at-pumps you’ve done recently we may require that you put more money in your account before authorising a pay-at-pump transaction.
You either need to wait for a few more days or put more money in your account (at least £100). This is to prevent people doing lots of £1 pay-at-pump transactions without enough money to pay for the fuel, and then leaving Monzo with a very large petrol bill we have to pay for, but can’t charge to our customers.
Given that ASDA has largely moved away from kiosk payments recently in favour of Pay@pump.
Additionally ASDA has traditionally not had a ‘shop’ style petrol station offering unlike the other main 3 supermarkets- Tesco, Sainsbury’s & Morrisons.