How to budget on an irregular income
For freelancers, agency workers, commission-based salespeople and anyone whose income this month looks nothing like last month's.
Almost all budgeting advice starts from the same assumption: a fixed amount arrives on the same day every month, and all that is left is to divide it up. The 50/30/20 rule, envelopes, automatic transfers the day after payday — it all rests on that.
When income swings from one to double, these methods do not hold. Worse, they make you feel you are failing, when it is the assumption that does not apply.
The mistake of the average
The first instinct is to work out an average. You add up the last twelve months, divide, and budget on that figure.
It is mathematically right and practically dangerous. An average is a figure you almost never receive: half the months fall below it. Budgeting on the average means organising your life around an income that, one time in two, does not arrive.
And the adjustment always goes the wrong way: in good months you do not cut back; in lean months you discover what is missing.
Start from the floor, not the average
Take your last twelve months and keep the lowest. Not the lowest reasonable one — the lowest, full stop, including the disastrous month you would rather forget.
That is your floor. Your running budget — rent, groceries, energy, insurance, transport — has to fit within that amount. If it does not, you are not keeping a budget: you are betting every month that it will be a good one.
It is an uncomfortable limit to set. It is also the only one that removes the fear of the lean month, because a lean month becomes a normal month.
A buffer account does the smoothing
The rest of the reasoning comes down to one simple idea: it is not your budget that should adapt to the month's income, it is an intermediate account that absorbs the difference.
Everything you earn lands in a receiving account. From there, you pay yourself the same amount every month — your floor — into your everyday account. Whatever is left over stays in the buffer.
You pay yourself a fixed salary. Good months fill the buffer, lean months drain it. Your everyday account never sees the difference.
A good month is not a rich month
This is the most expensive habit to unlearn. An unusually large payment does not mean you are earning more: most often it makes up for an earlier month or funds a later one.
An invoice paid late is not a bonus, it is catching up. Three jobs landing in the same week do not mean your income has tripled — just that the calendar bunched up.
Until the buffer has reached the target you set yourself, a surplus is not available. It is waiting to be allocated.
How much to aim for in the buffer
The answer depends on how widely your income swings, not on a general rule. A useful benchmark: the buffer should cover the gap between your worst month and your floor, as many times as you can string bad months together.
If your dips rarely last more than two months in a row, two to three months of running budget are enough. If they are seasonal and last a quarter, aim for the quarter.
Look at your own history rather than at advice. Thinking back over the past year, you already know how long your worst stretch lasted.
Annual costs are handled separately
Insurance, taxes, maintenance, energy balancing bills: these expenses do not follow the monthly rhythm and wreck any budget if you only discover them the month they fall due.
Add them up over a year, divide by twelve, and treat the result as a monthly cost — even if nothing goes out that month. You no longer suffer them; you have already paid them, one twelfth at a time.