Fair Bill Split for Unequal Incomes

When to use it

Two or more people share a home and its bills, and they earn different amounts. They want a split that both feel is fair, and they want to see the numbers before they talk about it. One set of figures in, one table and one conversation plan out, in one sitting.

Works for a couple, for housemates, or for adult family members sharing a home. Works for any currency.

Not for: deciding whether to open a joint account, how to own a property, or what happens to money if a couple separates. Not for budgeting each person's own spending. Not for splitting a single one-off bill such as a holiday, though the same arithmetic applies if the user asks.

What it asks you

Ask for everything in one numbered message.

1. Who is sharing, by first name or initial.
2. Each person's take-home pay per month, after tax and deductions, in the same currency. If pay varies, a typical month or an average of recent months.
3. The shared costs, each with its monthly amount: rent or mortgage payment, council tax or local tax, energy, water, broadband, food shopping, and anything else you share. Turn yearly or quarterly bills into monthly by dividing.
4. Any individual commitments you both agree should count before the split, such as one person's travel to work or a loan they were already paying. Only ones you both accept.
5. Any method you have already tried or one of you prefers.

Work from what comes back. If a figure is missing, leave it out and say so; never estimate a bill or a salary. If pay is given weekly or yearly, convert it and show the conversion (weekly times 52 divided by 12; yearly divided by 12). If one person gives gross pay, ask for take-home, saying in one line that splits on gross pay favour whoever pays more tax. Never invent a number.

What comes back

Plain text. Headings in capitals. Amounts with the currency symbol and two decimal places (or the currency's own minor unit).

THE INPUTS Each person's take-home pay, any commitments counted, the income each brings, and the list of shared costs with the total. Combined income.

SIDE BY SIDE A table: one row per method, columns for what each person pays, what each keeps, and each person's share of income spent on the home.

THE WORKING Each method's arithmetic, one or two lines each, with the rounding rule applied and the total checked.

TRADE-OFFS Three to five lines, about these numbers. Who gains and loses under each method, in money per month.

TO AGREE Four to six questions to talk through together.

FLAGS Anything from Refuse or flag that applies. "None" if none.

Next: one line naming the single most useful step, usually choosing a method and a date to re-run it.

• 00_START_HERE.pdf: the two-minute set-up for each AI.
• 1 - Skill: fair-bill-split-unequal-incomes.zip, one upload to Claude, ChatGPT, Gemini, Grok or Microsoft 365 Copilot. It switches on by itself when this job comes up.
• 2 - Text file for any AI: the same Move as one .txt. Attach it to any chat, on any plan, and type "Follow this file".

It drafts, you read and send. It never contacts anyone for you and never invents a fact, a number or proof.

A Move is a single play. The whole function in a box is an agent pack.