In a shared flat you split rent, electricity, groceries and more. To keep things relaxed, you need a clear, traceable way to settle up.
Rent and internet are usually fixed and split evenly. Groceries and spontaneous expenses vary. Keep the two cleanly separated so it's clear at the end of the month who owes what.
Most roommate conflicts about money come from a lack of transparency. When everyone can see their status at any time, there's no more arguing about who still owes what.
A monthly settlement works well – often enough that large amounts don't build up, rare enough that it doesn't become a hassle.
Via receipt scan: photograph the receipt, the line items get recognized, and you assign who had what.
