Moving in together: what nobody tells you

Everyone tells you about the fun part: the keys, the first night, the first time you say "our flat". Fewer people tell you about the rest, which is where most of the first year is spent. Here it is, in roughly the order it arrives.

Have the money conversation before the van

Not "we'll sort it out". Before. How much does each of you earn, roughly, and how much does each of you owe? Who pays what, and in what proportion? If one of you earns twice as much as the other, does rent split in half or in proportion? Who buys the sofa, and whose is it if you split? What happens to the big shared bills if one of you loses a job?

These are awkward questions to ask the person you love, which is why so many couples do not, and why so many first-year rows are about money without ever being about money. A shared account for the shared bills, each paying in a fair share, with your own money kept separate, is the arrangement most couples arrive at eventually. Arriving at it on purpose, before resentment has built, is better.

Know what you are signing

A joint tenancy makes each of you liable for the whole rent. Not your half, all of it. If your partner leaves or stops paying, the landlord comes to you. Ending the tenancy usually needs both of you to agree. If one name is on the tenancy and one is not, the one who is not has very little security and can be asked to leave. Neither arrangement is wrong, but know which you have.

If one of you owns the place and the other moves in, the one moving in builds up no stake in it, however much they pay towards the mortgage, unless something is written down. In England and Wales there is no common-law marriage. However long you live together, you have no automatic claim on each other's property, pension or income if you separate. Scotland gives cohabitants a limited claim, with a short deadline. A cohabitation agreement sounds unromantic and takes an afternoon. People who have separated without one tend to wish they had spent the afternoon.

The first three months

Expect irritation. You are discovering how the other person actually lives: the dishes left to soak overnight, the thermostat, the phone call to their mum every evening, the way they fold or do not fold. Most of it is habit, not character, and most of it stops being noticeable by month four.

What tends to help is saying things small and early rather than letting them become a position. "Can we agree the washing-up gets done before bed?" on day eight is a conversation. The same sentence shouted in week nine is a row with a history.

The invisible ledger

Housework is where moving in most often goes quietly wrong. Someone starts doing more, usually without either of you deciding so, and within a year it has become how things are. Noticing what needs doing is work too, and it is usually the same person doing the noticing and the doing. Sit down once, list everything the household needs, and divide it on purpose. Revisit it when something changes: a new job, a longer commute, a baby.

Keep a life of your own

Moving in is not merging. You both still need friends who are yours, evenings that are yours, and a corner of the place that is yours. Couples who do everything together from the day the van arrives tend to find within a year that they have nothing to tell each other.

One thing to watch for

Most of the above is ordinary, and most couples muddle through it well enough. One thing is not ordinary, and it is worth naming once because moving in is so often where it starts.

If sharing a home arrives with new rules (about who you can see, when you need to be back, what you spend, where your phone is, how you dress), or if you find yourself explaining your evenings and softening your plans to avoid a reaction, that is something with a different shape from the settling-in period, and it tends to grow rather than fade. What is coercive control? describes it plainly, so that you know what it looks like whether you ever need to or not.

For everyone else: the dishwasher argument is normal, the thermostat argument is eternal, and you will almost certainly be fine.