Three of you move in. The rent splits three ways, the electricity too, and very quickly somebody suggests a joint account “to keep it simple”. Six months later nobody knows who fronted what, and the joint account has become the subject of the flatshare rather than its tool.
There is another way: each keeps their own account, and only what is genuinely shared gets shared.
The rent, and only the rent
Not all spending in a flatshare is alike. Rent, electricity and internet arrive every month, for the same amount, and concern everyone. Groceries vary. Each person’s mobile plan is nobody else’s business.
Putting all three in the same pot means sorting it out afterwards, and sorting things out between three people is exactly what you wanted to avoid.
The dividing line is easy to draw: a cost is shared if its absence would affect everyone. Electricity, yes. The pasta in the cupboard, yes, if it belongs to all. Someone’s headphones, no, even bought the same day.
One split per charge
Equal when that is obvious. By income when the difference is real and everyone has said so. By hand when one bedroom is larger, or one person has no car.
What matters is not the split chosen, it is that it is said once, written down somewhere, and the same next month. A rule renegotiated monthly is not a rule.
Two cases deserve their own split. Very unequal bedrooms: a 9 m² room and a 16 m² room in the same flat are not worth the same share of rent, and saying so at the start avoids thinking it for two years. Long absences: someone away on placement for three months keeps paying rent, since the room stays theirs, but not necessarily the groceries.
Who fronts what
This is the question people forget, and the one that creates tension.
Every shared charge is debited from somebody. Electricity from one, internet from another, insurance from the third. Each watches their account fall and none has the total: the person fronting 180 € a month feels they are carrying the flatshare, even if it all evens out in the end.
Balancing the advances at the start solves the problem before it exists. Spread the debits so that each fronts roughly the same. That is five minutes of conversation in the first month, and none afterwards.
What stays private
Each person’s own budget does not leave. What somebody spends outside the shared charges is no business of the flatshare, and an app that mixes the two forces a choice between keeping your accounts and keeping your life to yourself.
You can have both: what is shared gets shared, the rest never leaves.
It is also what makes the method last. A flatshare where everything is visible becomes a flatshare where people justify themselves, and nobody keeps that up for more than a year.
Settling the month
At the end of the month, everyone has fronted something. Rather than six criss-crossing transfers, you net them off: if A owes B 40 € and B owes C 30 €, a single transfer can be enough.
That is arithmetic, not diplomacy. And it is the kind of sum you are glad not to do yourself on a Sunday evening.
Pick a day and keep it. The 5th, once the start-of-month debits have gone through and the real amounts are known. A settlement that happens “when we think of it” does not happen, and the balances pile up until they become a subject.
Groceries, the case that resists
Fixed charges are easy: an amount, a date, a split. Groceries are not. They vary, different people buy them, and part of what is bought is only half shared.
Three methods work, and you have to choose one.
Everything shared: each notes what they front, and it is split at month end. Fair, and requires noting.
A fixed shared budget: each puts 150 € a month into a pot, and groceries come out of it. Simple, and creates a pot to watch.
Each for themselves, except the basics: toilet paper, cleaning products and oil are shared, the rest is personal. Less fair, and almost argument-free.
The third works better than it sounds, especially when eating habits differ a lot.
To settle on day one
The list of shared charges, with amounts and dates. The split for each. Who fronts what. The monthly settlement day. And the method for groceries.
Five decisions, half an hour, between three people. It is the best half hour of the whole flatshare.