The flatmate ledger that survives a whole year

Flatshares don't fail over rent. They fail over the ₹340 of milk and bread that one person keeps buying, the electricity bill that lands in one person's name, and the plumber nobody wanted to call. The amounts are small and the resentment compounds monthly.

Here is a system that takes twenty minutes to set up and about thirty seconds a week to run. Three flatmates, one flat, real numbers.

The twenty-minute setup

1. One group. Named for the flat, in your currency, with everyone in it. Not one group per bill: one group, forever.
2. Recurring lines for the fixed costs. Rent on the 1st, internet on the 5th, the cook on the 1st. They log themselves from then on, with the split you agreed once.
3. An agreed settle date. The 3rd of the month, say. Put it in the calendar. It is far easier to pay on a date than to decide when to ask.
4. A spending line. Anything over ₹2,000 on the flat's behalf gets a message first. Below it, just buy it and log it.

What goes in the group, and what doesn't

In: rent, utilities, internet, cook and cleaner, shared groceries, gas, repairs, the shared streaming subscription, anything for the flat itself. Out: your own food deliveries, your own laundry, the friend who stayed a weekend, anything you'd be uncomfortable itemising to the other two.

Your personal spending doesn't disappear. It lives in your own ledger in the same app, with its own categories and its own monthly report. That's the point of having both halves in one place: the flat's money and your money stop being two separate mental systems.

A full month

Rent is split 40 / 32 / 28 by room size. Everything else is equal. Groceries were eleven separate trips by whoever was passing the shop.

Two transfers close the month: Meera sends Rohan ₹10,460.00 and Kabir sends Rohan ₹12,290.00. Five expense categories, fifteen individual entries, thirty seconds of settling.

The five rules that make it survive a year

• Log at the shop, not at home. The entry takes ten seconds while you're standing at the counter and never happens once you've put the bags down.
• Name things properly. "Groceries: milk, bread, detergent" not "stuff". Nobody queries a line they can picture.
• Never round. ₹1,127 is ₹1,127. Rounding to a nice number feels generous once and feels like a tax after four months.
• Fix mistakes, don't relitigate months. Edit the wrong entry, say what you changed, move on. Reopening a settled month is how a flat stops trusting the ledger.
• Keep the deposit out of it. It isn't an expense. Record who paid what into it, and settle it against whatever the landlord actually returns.

When someone moves out

Settle the group to zero on their last day, not "we'll sort it once the deposit comes back", which is how ₹18,000 ends up owed to someone who's moved cities. Then handle the deposit as its own conversation, with its own numbers, in writing.

Pro-rate their final month by day: a ₹15,360 share for 20 days of a 31-day month is ₹15,360 × 20 ÷ 31 = ₹9,909.68. Log it as an exact-amounts split, add the new flatmate, and the recurring lines carry on as if nothing happened.