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Flatmate expense tracker for rent and bills

The fairest way to split bills with flatmates is to log every shared bill in one place, split rent by an agreed share, and settle the net balance every month or two. Here is a real month, worked through.

Updated November 2026

Living with flatmates means a steady stream of small shared bills on top of the rent. Energy, broadband, council tax, cleaning supplies, the odd takeaway. Each one is easy to split. Together, across months, they become the thing people quietly resent. A shared tracker keeps it fair and visible to everyone.

Worked example: a 3-bed flat in London

Priya, Tom and Sam share a flat with a monthly rent of £2,400. Tom has the biggest room, so they agreed rent shares of £900, £800 and £700. Everything else is split equally. Tom pays the landlord, and the others pick up bills.

The shared bills come to £408, which is £136 each. Add that to each person's rent share to get their fair share for the month:

A plus balance means the group owes you. A minus balance means you owe the group.

Tom is owed £1,364. Priya owes £750 and Sam owes £614, which also adds up to £1,364. So the month settles in two transfers:

1. Priya pays Tom £750
2. Sam pays Tom £614

Why a tracker beats a spreadsheet for flatmates

A spreadsheet works until someone forgets to update it. With a shared group, whoever pays adds the bill from their phone, and everyone sees the new balance. There is no single "money person" doing admin for the flat. Comments on each expense hold the context ("this includes the late fee") and the activity feed shows what changed and when.

You also do not need to settle every month. Many flats let balances run and square up every couple of months, or when someone moves out. The balance is always there, worked out from every bill so far.

How to set it up in SplitSimple

1. Create a group for the flat. Name it after the address and set the currency to £.
2. Invite your flatmates by link. Send the link in your flat chat. It opens in any browser, or in the Android app.
3. Add the rent with an exact split. Enter each person’s agreed share. If you split by percentage instead, choose percentage and enter the shares.
4. Add bills as they arrive. Use an equal split for shared bills. Leave someone out if a cost was not theirs.
5. Settle up when it suits you. Settle up shows the fewest payments. Pay by bank transfer, then mark it as paid so the balance resets.

Tips for roommate bill splitting

• Agree on what counts as shared. Toilet roll and washing-up liquid usually do. Someone's oat milk usually does not.
• Decide the rent split once. If rooms differ, use our guide to splitting rent fairly and write the agreed numbers down.
• Add bills when they are paid, not when they are due. The person who paid should get credit straight away.
• Settle before anyone moves out. It is much easier while everyone still shares the same front door.

FAQ

Related

• Rent split calculator
• How to track shared expenses with roommates
• How to split rent fairly
• How to split the electricity bill with roommates