How to split roommate, household and group expenses fairly

Short version: create a group for the people you share costs with, split each bill equally, by exact amounts or by percentage, and record everyone who paid. SplitExpenZ keeps one list of who owes whom that the whole group can see. For a one-off dinner, Quick Split works from a link, and nobody has to sign up.

Which kind of group should you create?

SplitExpenZ has seven kinds of group: Home, Trip, Foreign trip, Couple, Friends, Work and Other. Pick the one that describes the spending: Home for a flat or a family household, Couple for two people sharing a life, Friends for a regular group that eats out together, Work for office lunches or a team outing.

The type is mostly a label that keeps your list readable. The one that changes how a group works is Foreign trip, which asks which currency the group settles in. Every other group settles in the currency of the person who created it. If you are going abroad, read how to split trip costs when you pay in several currencies first.

It usually helps to keep separate groups for separate arrangements. Rent and utilities with flatmates is one group. A weekend away with the same people is another. That way the flat's balance isn't mixed up with who paid for the petrol.

Equal, exact or percentage: which split is fair?

"Fair" is whatever the group agreed. The app's job is to record that agreement exactly. Each bill can be split one of three ways:

• Equally, when everyone uses something about the same: internet, cleaning supplies, a shared takeaway.
• By exact amounts, when you know who had what, such as a grocery run where one person bought their own items. The amounts have to add up to the bill.
• By percentage, for an agreed ratio, such as a bigger room paying a bigger part of the rent. The percentages have to add up to 100.

Here is an illustrative example with made-up numbers. Three flatmates agree that the person in the largest room pays 40% of the rent and the other two pay 30% each.

When an equal split doesn't divide exactly, the app shares out the leftover smallest units so that the shares always add up to the bill. Nobody is left covering a missing paisa. Group bills are added one at a time, so a monthly cost like rent is added as a new bill each month.

What if more than one person paid?

It happens all the time: the weekly shop goes partly on one card and partly on another. Record it as one bill with several payers, each with the amount they put in. The amounts have to add up to the bill. On the web, turn on "Paid by more than one person".

Recording one bill with two payers is better than two half-bills. The receipt matches the bill, and if the amounts are ever questioned, there is one place to look.

How do you add people to a group?

You can add people by email, with an invite link you send however you like, or, in the mobile apps, from your phone's contacts. Contacts access is optional. On the web, you can also pick from your friends or from people you invited recently.

Everyone in the group sees the same bills and the same balances. That shared view is most of the point: nobody has to take one person's word for the totals.

What happens when someone leaves?

Flatmates move out and friends drift away. Before someone leaves, their balance in the group has to be settled to zero, and any trip money they still hold or own has to be spent, handed over or changed back. An admin who is leaving must first make someone else an admin, so the group is never left without one.

After they leave, their bills and payments stay in the group's history. Past spending still adds up, and the remaining members' balances don't change because someone moved out.

How does the list of who owes whom work?

SplitExpenZ works out each person's overall position from every bill and payment in the group: what they paid, minus their share. It then turns those positions into one list of payments. Because it works from overall positions, you don't repay each other bill by bill. If Dev owes Riya for groceries and Riya owes Dev for electricity, those cancel before anyone pays anything.

The list doesn't promise the fewest possible payments in every case, but the payments are exact and, once made, bring everyone to zero. When someone pays, record it and the list updates for everyone.

SplitExpenZ never holds or moves money. It keeps the arithmetic, and you pay each other the way you usually do.

How do you split a one-off dinner without sign-ups?

Not every split needs a group. For a single dinner or a day out, Quick Split creates a split for 2 to 20 people and gives you a link to share. Your friends open it in a browser, with no account and no download, and it works out who owes what.

A Quick Split is temporary. It expires 30 days after it is created, so it suits one-off events. For anything ongoing, like a flat or a regular group, a proper group keeps the history.

Want to see your own spending next to what you share? Read how to track your personal spending alongside shared expenses. To see what is free and what the optional Premium subscription adds, see pricing.