How to build your company's income statement
The income statement answers whether the business is profitable. Built correctly, it shows exactly which line destroys the result: price, cost, structure or taxes.
An income statement is built as a cascade: gross revenue, minus sales deductions and taxes equals net revenue; minus variable costs equals contribution margin; minus fixed expenses equals operating result (EBITDA); minus depreciation, interest and income taxes equals net profit. It uses accrual accounting — the date of the event, not the date of payment.
The cascade structure
Each line subtracts a different kind of cost, which is why the P&L pinpoints the problem:
- Gross sales revenue
- (–) Deductions, returns and sales taxes = Net revenue
- (–) Variable costs (COGS, commissions, freight) = Contribution margin
- (–) Fixed operating expenses = EBITDA
- (–) Depreciation, financial result and income tax = Net profit
Accrual vs. cash basis
The P&L uses accrual: a sale split into six installments appears fully in the month of the sale, while cash records it across six months. Mixing both bases is the most common distortion in small companies.
Contribution margin and break-even
With contribution margin in hand, break-even equals fixed expenses divided by the margin percentage — the revenue needed to avoid a loss.
Common mistakes
Treating owner salary as profit distribution, lumping all costs into one generic account, ignoring sales taxes and mixing investments with expenses are the four most frequent errors.
A few minutes, no cost.
Frequently asked questions
What is an income statement used for?
It shows whether the company made a profit or a loss in a period, and which line consumed the result.
What is the difference between a P&L and a cash flow?
The P&L measures profit on an accrual basis; cash flow measures money in and out on the actual date. A company can be profitable and still run out of cash.
How often should I close the income statement?
Monthly, within the first ten business days, compared with the previous month and the same month last year.
Can I build an income statement in Excel?
Yes. A well-structured management P&L in a spreadsheet covers most small and mid-sized companies.