Budgeting on Commission-Based Income: The Lowest-Month Method

A budget built around your average commission month works fine — until you hit a month below average, which for most commission-based earners happens more often than the word “average” suggests. The fix isn’t a different app; it’s budgeting off a different number entirely.

Budget Off Your Lowest Month, Not Your Average

Pull your last 12 months of commission income and find the single lowest month — that number, not your average, becomes your baseline for covering fixed costs: rent or mortgage, utilities, insurance, minimum debt payments, and groceries. If your fixed costs fit inside your worst month on record, a bad month stops being a crisis and just becomes a normal part of the income pattern.

Use a Zero-Based Budget Built to That Baseline

Set a zero-based budget — every dollar of your baseline income assigned to a category until income minus expenses equals zero — using the lowest-month number as your income line, not a projection for the current month. Anything earned above that baseline in a given month doesn’t get spent on lifestyle upgrades by default; it has a job waiting for it (see below).

Build a Buffer From the Good Months

Every dollar earned above your lowest-month baseline goes into a dedicated buffer account, which then funds the gap in any month that comes in below baseline. This is the mechanism that actually makes irregular income livable: the buffer, not the paycheck, is what your fixed bills draw from month to month, so timing mismatches between income and bills stop mattering.

Pay Yourself From Last Month, Not This Month

A related technique many high-commission earners use: fund this month’s budget entirely from last month’s actual income, not a forecast of what this month might bring. That turns every month into a “known number” budgeting exercise instead of a guess, and pairs naturally with the buffer approach above — between the two, commission income behaves like a predictable paycheck by the time it reaches your budget, even though the underlying income never was.

Written by Samuel, Certified Public Accountant

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