Mileage vs petrol receipts

Hi - my husband has historically claimed all his petrol receipts ( as a sole trader using his own work van to get to building sites from our home). This year he's driven 10,396 miles so I'd like to claim the £4599 instead of claiming petrol ( I understand you can only do one or the other) I'll be omitting the MOT expense too. My question is - are we allowed to change from claiming petrol receipts to claiming mileage instead from one year to the next or should I stay consistent & not change from my previous way of claiming for petrol receipts? It's obviously more tax efficient for us to deduct the mileage for this 23-24 tax year. Many thanks in advance!

Hi LisMur,
You cannot change your way of calculating unless you actually change vehicvle, so if using the same vehicle as last year you will need to continue with actual expenses.
Thank you.