A budget has one job: tell you, before the month starts, what you intend to earn and spend. If it takes an afternoon to update and nobody reads it, it is not a budget. It is a spreadsheet with a name. One page, updated monthly, beats twenty tabs updated never.
Build it from the money you already handle
Pull three months of bank statements and group every transaction into ten or twelve categories. Resist the urge to create a category for every supplier. The right number of categories is the number you will actually review, usually fewer than fifteen.
These historical figures become your baseline. A budget is a set of decisions about how the next month differs from the last one, and you cannot make those decisions without an honest starting point. Expect the baseline to be uncomfortable. Most owners find at least one category that is larger than they assumed and one they had forgotten entirely, and both discoveries are cheaper now than at the end of the year.
Three blocks, in this order
Start with money coming in. Split it into committed revenue, likely revenue and speculative revenue, and budget only against the first two. Then money going out, split into fixed costs that arrive whether you trade or not, and variable costs that rise with sales.
Finish with what is left. That figure, not the revenue line, is the number that determines what the business can do next. If it is negative before owner pay, the model needs changing rather than the spreadsheet.
Put dates on the lines
Timing is where budgets fail. Rent leaves on the first, insurance leaves annually, tax arrives quarterly, stock is bought before a peak. A monthly total hides all of that and produces false confidence in the middle of the month.
Add a small column for the day each cost lands. When two large payments fall in the same week, you can move one before it becomes a problem rather than after.
Choose a margin target and protect it
Decide the gross margin the business needs and check each month against it. Without a target, a busy month feels like a good month even when the work was bought at a discount that erased the profit.
When you miss the target, look at three causes in order: prices too low, costs too high, or mix of work shifted toward low-margin jobs. Each has a different fix, and guessing between them wastes a quarter.
A budget is not a prediction of the future. It is a statement of the trade-offs you have already agreed to make.
Keep a contingency line you will not raid
Set aside a percentage of fixed costs each month for the things that break. Label it clearly and keep it in a separate account if you can. A contingency that sits in the operating account tends to be spent on something that felt urgent in week three.
Review the contingency quarterly. If it has never been touched, either you are lucky or the business is underinvesting in maintenance. Both are worth knowing.
The monthly review, twenty minutes
Compare actual against budget, line by line, and explain only the differences above a threshold you set, perhaps ten percent or a fixed amount. Write one sentence per difference. Then adjust next month and stop.
Do not rebuild the whole budget every month. Small corrections repeated twelve times produce a more accurate picture than one heroic annual exercise, and they take a fraction of the effort.
One-page budget checklist
- Baseline built from three months of real transactions
- Twelve categories or fewer, each with an owner
- Revenue split into committed, likely and speculative
- Fixed and variable costs separated
- Payment dates noted beside large items
- Gross margin target stated at the top
- Contingency line held in a separate account
- Monthly review booked, twenty minutes, differences explained in one line each
Print it. A budget on paper gets annotated; a budget in a folder gets forgotten. Keep the printed page where you work, not in a drawer, and write the month's one big deviation at the top in pen. Keep last month's version beside this month's, because the comparison is where the value sits, and the pattern across three months tells you more than any single figure.
