How to split bills in a shared house without fighting about it

Anyone who's lived in a share house knows: most arguments aren't really about money — they're about the lack of an agreed method. Nobody minds paying their share; the problem is when the method changes from bill to bill, or nobody remembers who paid what.

The good news: there are really only three ways to split a bill between roommates, and picking the right one for each type of expense solves most of the friction before it even starts.

The simplest option: divide the total by the number of roommates. Works well for bills everyone uses equally — internet, streaming, shared cleaning supplies.

Where it breaks down: rooms with different sizes or setups (one has air conditioning, another doesn't), or when someone's away travelling for most of the month and barely uses the house.

Each roommate pays a fixed percentage, agreed in advance — usually based on room size or income. It solves the unequal-rooms problem without recalculating everything every time a new bill lands.

It's the most common method for rent in houses with rooms of very different sizes (ensuite vs. a small single, for example).

Everyone pays what they actually used — the room with AC pays more on the power bill, whoever cooks the most pays more on gas. It's the fairest method, but also the one that needs the most bookkeeping: someone has to track different amounts per person instead of just dividing one total.

This is where most houses give up trying to do it manually — in a spreadsheet or a group chat, this kind of tracking falls apart fast.

• Agreeing on a method verbally, with nothing written down — after two or three bills, nobody remembers what was agreed.
• "I'll cover this one, you get the next one" with no record — turns into a misunderstanding a few weeks later, because everyone remembers it differently.
• Splitting bills from memory, with no history — makes it hard to figure out who's already paid what when a question comes up.
• No due-date reminder — someone always forgets, and the bill goes late or racks up a late fee before the rest of the house notices.