I'm not frightened of direct debits. It's very common in the UK. My point is, regardless of the rules, there is no immutable natural law or supernatural power making everything go right - all business systems requires a level of trust. From experience, I trust the DD system to a degree at the moment, far enough to be confident that they'll either do the right thing or rectify mistakes quickly and without too much hassle.

I allow one of my cc to take the full amount automatically, the others I just allow the minimum and transfer the remainder myself. But I'm cash-rich right now so it's no biggy.

The key phrases are "right now' and "at the moment" . Things can change. By "trust" I don't mean "blind faith" .