If you rent a diesel and it needs adblue is it classed as a consumable and you pay or service item and they pay.

Just rented a velar r dynamic from k2 prestige in London for a couple of weeks(ffrr not avail) and adblue 500ml warning on when collecting. They wisked it away and topped it up while I waited, this had me wondering the above question.

What has been your experience? it is better to have and not need then need and not have