Should your partner pay rent when they move into your place?
One person already lives somewhere and the other is moving in. It is one of the most common ways a shared household starts and it arrives with an awkwardness that two people signing a new lease together never face: there is an existing arrangement, it belongs to one of you, and the other is joining it.
The question of whether they should contribute has an easy answer. The question of how much has a genuinely complicated one, and it depends almost entirely on whether you rent or own.
If you rent, it is mostly simple
The rent is a cost the household now shares, and it gets split the way you would split any other: evenly, or by income, using whichever you have agreed for everything else. The fact that one of you found the apartment first does not change what it costs.
Two practical things to sort in the same conversation. Whether the arriving person goes on the lease, which is a question for the landlord and has real consequences for both of you. And what happens to the deposit, which one person has already paid and which is now protecting a home two people live in.
If you own, half the mortgage is the wrong number
This is where most of these arrangements go wrong, and it goes wrong in good faith, because half the mortgage feels like the obvious equivalent of half the rent.
It is not, because a mortgage payment is doing two different things. Part of it is the cost of housing — interest, insurance, maintenance, tax. The rest is buying equity in an asset that belongs entirely to the person on the title. Somebody paying half of that is funding the other person's ownership, and they will have nothing to show for it if the relationship ends.
The test is what each person walks away with. If one of you leaves after three years having paid half a mortgage and owning none of a house, the arrangement was not what it looked like.
Two defensible alternatives. Work out what the place would rent for and split that figure, which prices the housing rather than the asset. Or have the arriving person cover a larger share of the running costs — utilities, groceries, insurance — while the owner covers the mortgage alone. Both are common and both survive being explained out loud, which is the real test.
Everything that is not rent
Utilities, internet, groceries and shared subscriptions become shared costs on the day somebody moves in, and they need the same explicit agreement rent gets.
In practice they rarely get it. Rent is discussed because it cannot be avoided, and the rest is left to work itself out — which is how you arrive, eight months later, at a household where one person is on every account and has stopped mentioning it.
The conversation nobody wants to have
It is worth agreeing, at the start, what happens if it does not work out. Not because anybody expects that, but because this is the only moment when both people can discuss it as a hypothetical rather than as a live situation.
How much notice. What happens to a deposit one person paid. Whether anything bought jointly for the home is jointly owned. Five minutes at the start, and it is the difference between an unpleasant month and a much worse one.
Once you have agreed the split
Something has to apply it every month.
Pairly holds the rent, the bills and who pays what, splits them evenly or by income, and keeps a running total of who has covered more. Both of you see the same month.