How to write a roommate agreement about money

A roommate agreement is not a legal document and does not need to be one. It is a written record of what everybody thought was agreed, which is useful precisely because memory is not — and the value of it is almost entirely in the two or three items nobody would have thought to discuss out loud.

The six that belong in it

• What each person pays, and on what date it leaves their account.
• Which bills are shared and which are not, named individually rather than as “the bills”.
• Whose name is on the lease and on each utility account.
• How the deposit is handled if somebody leaves before the end.
• What notice somebody gives before moving out, and whether they must find a replacement.
• Who is responsible for the shared things that were bought together.

The two everybody leaves out

The first is guests. Not house rules about them, but money: at what point does somebody staying regularly become somebody using the utilities, and what happens then. Households that have never discussed it discover their view of it during an argument about something else.

The second is what happens to shared purchases. The sofa, the kettle, the television everybody chipped in for. It has no obvious owner, it cannot be divided, and the person leaving usually assumes they are owed something while the people staying assume they are not.

Write it before anybody has moved in

The right moment is the week before, when none of it is about anybody. The same conversation in month four is about a specific incident and a specific person, and it arrives with a defence already attached.

It does not need signing, printing or witnessing. A message in the group chat that everybody has read is enough for the job it does, which is to be checkable later.