I've found the best one for me is the good old paper notebook. As we say in Spain, "en casa de herrero, cuchillo de palo" ("at the blacksmith's house; wooden knives", or something along those lines, hard to translate 😅).

I think that is slowly changing right? I know of at least a couple countries where e-invoicing is slowly being mandated. It's difficult to make all companies change their invoicing processes though.

That's so useful! Thank you 💝