Blaming baby brain here, seem to be over-thinking.
My OH wants a credit card to build up his rating. It’s not awful, but not great.
Anyway, if he got one to buy petrol on for example and pay it off in full every month does this really help over a period of time? If so, should he wait a few days for the spend to show and then pay it off asap, or should he set up a DD to cover the full balance?