Today is an exciting day: we’re launching what has been our most-requested feature for a long time. We’re calling it “debt shuffling,” but it’s best explained with an example. Say this is you and your friends:

The arrows mean “owes money to.” There are only seven friends here, but they will have to write 21 checks to settle up!
Enter debt shuffling. Any one of these people can click the “shuffle debt” button, which will take you to a screen like this:

The monk will think of a way to reduce the number of checks you have to write to settle up. This debt shuffle will take the complicated graph above and turn it into this!

We go the extra mile when we’re proposing a debt shuffle by paying attention to how many bills you’ve split with each person in the group (and how recently those bills happened). If you split bills with some people more often than others, you probably see them more often, and those are the people it will be easiest to settle up with.
We were thinking hard about privacy as we were developing this feature. How do we make it useful without giving away information about your private debts? Here’s what we came up with. You get to see the effects of the debt shuffle on you (that’s the “before” and “after” display above). You also get to see how the money was shuffled around (that’s the “Check the math” section above) — this lets you verify that the debt shuffle was fair. What you don’t get to see are the balances between your friends before or after the shuffle.
We really hope you enjoy this feature as much as we’ve enjoyed developing it! Debt shuffling takes the convenience of BillMonk’s “social money” concept to the next level.