MONEY · HOUSEHOLDS

How to split household bills fairly

Most bill arguments are not about money. They are about a rule nobody agreed to in advance. Pick a method, write it down, and the monthly conversation disappears.

Last reviewed 23 September 2026.

First, agree what is shared

Write two lists: shared and personal. Rent or mortgage, utilities, internet, home insurance, groceries and shared subscriptions usually sit on the shared list. Personal phones, individual streaming, personal travel and individual debts usually do not.

Do this before choosing a method. Nearly every argument about splitting is actually an argument about whether something belonged on the shared list.

Method one: equal shares

Everyone pays the same amount. Simple, transparent, and fair when incomes are broadly similar.

Example: shared costs of $2,400 a month between two people is $1,200 each. Its weakness shows when one person earns far less — the same dollar amount takes a much larger bite out of their life.

Method two: shares by income

Each person pays the same percentage of their income. Add the incomes, find each share, apply it.

Example: one person earns $4,000 a month and the other $2,000. The total is $6,000, so the split is 67 and 33 per cent. On $2,400 of shared costs that is $1,600 and $800. Both are giving up the same proportion of what they earn.

Method three: by usage, and the hybrid

Usage-based splitting suits specific bills — someone who runs a workshop at home, or a vehicle only one person drives. It is precise but tedious as a whole system.

The hybrid is what most households land on: fixed housing costs split equally or proportionally, and usage-based costs paid by the person who generates them. Write down which bills follow which rule.

Making it run itself

Pick one payment date, one account the shared money lands in, and one person responsible for each bill. Automate the transfers so nobody has to chase anybody.

Review it when circumstances change — a new job, a lost job, a new baby, someone moving in or out. In HAUSINE, shared bills and who owes what live in My Money, so the record is the same one everyone sees.

Common questions

What is the fairest way to split bills?

There is no single answer, but the two that hold up best are equal shares when incomes are similar, and income-proportional shares when they are not. Proportional splitting means each person pays the same percentage of their income rather than the same amount.

How do I split bills when we earn very different amounts?

Add both incomes, work out each person's share of the total, and apply that percentage to the shared costs. Someone earning 60 per cent of the household income pays 60 per cent of the rent. It leaves the same proportion of freedom on both sides.

What counts as a shared cost?

Agree this first, because it is where disputes start. Rent or mortgage, utilities, internet, insurance, groceries and shared subscriptions are typically shared. Personal phones, individual subscriptions, personal transport and individual debts usually are not.

Should we open a joint account for bills?

A shared account that each person pays a fixed amount into each month is the simplest way to run it, and it makes the record obvious. Keep personal accounts alongside it so nobody has to explain every purchase.

Official sources

Whatever you agree, write it down and revisit it when someone's income or circumstances change. A fair rule from two years ago can be an unfair rule today.