What a P&L actually is
A Profit & Loss statement (also called an Income Statement) shows what happened in your business over a period of time — a month, a quarter, a year. Money came in (revenue), money went out (expenses), and the difference is your profit or loss.
The P&L is different from your bank account in an important way: it doesn't show you cash. It shows you economic activity. You can be profitable on the P&L and broke on cash if your customers haven't paid yet. You can be unprofitable on the P&L and flush on cash if customers paid for work you haven't delivered yet. Both reports matter — the P&L tells you whether the business is working; cash tells you whether you can operate it.
The structure of a P&L
Every well-organized P&L follows the same basic structure:
- Revenue (or Income, or Sales) — what customers paid you for goods or services
- Cost of Goods Sold (COGS) — direct costs to produce or deliver what you sold
- Gross Profit — Revenue minus COGS
- Operating Expenses — everything else it takes to run the business (rent, marketing, software, admin labor)
- Operating Profit (or Net Operating Income) — Gross Profit minus Operating Expenses
- Other Income / Expenses — interest, gains or losses on asset sales, non-operating items
- Net Income — the bottom line, what's left after everything
If your P&L doesn't have a clean separation between COGS and Operating Expenses, that's the first thing to fix. The split matters more than people realize.
Reading the revenue section
Don't just look at total revenue — look at composition.
- Multiple revenue lines — break revenue into categories that mean something for your business. Service revenue vs. product revenue. Recurring vs. one-time. By customer segment if relevant.
- Refunds and discounts — should be visible separately, not netted away
- Sales tax collected — should never be in revenue (it's a liability, not income)
- Trend — compare this period to last period and to the same period last year
What to watch for: a single revenue line called "Sales" with no detail. That's a P&L that can't tell you which part of the business is growing.
Reading Cost of Goods Sold (COGS)
COGS includes only the direct costs of what you sold during the period:
- For a product business: inventory cost, manufacturing labor, packaging, freight in
- For a service business: labor of the people delivering the service, subcontractor costs, materials used on the job
- For a restaurant: food and beverage costs
- For a contractor: materials, subcontractors, direct labor on jobs
What's not COGS: rent, admin salaries, marketing, software, owner pay. Those are operating expenses. The line is direct vs. indirect — if the cost happens because of a specific sale, it's COGS. If it happens because the business exists, it's an operating expense.
Why this matters: gross profit margin (Gross Profit ÷ Revenue) is one of the most important numbers in your business. Mixing operating expenses into COGS destroys this number and hides whether your core economics work.
Reading the gross profit margin
Gross profit margin tells you how much of every dollar of revenue is left after you've paid the direct costs of producing it. Industry-typical ranges (very rough):
- Service businesses — 50–75%
- Restaurants — 60–70% (food only); 30–40% after labor included as COGS in some models
- Retail — 30–50%
- Construction / contractors — 20–35%
- Software / SaaS — 70–85%
- E-commerce — 30–50% (varies wildly by product category)
If your gross margin is well below the typical range for your industry, you have a pricing problem, a cost problem, or both. Operating expenses can't fix a broken gross margin — they can only make it worse.
Reading operating expenses
Operating expenses (sometimes called Overhead or SG&A — Selling, General, and Administrative) should be organized into categories you actually care about:
- Payroll (admin and overhead staff, not direct labor)
- Rent and utilities
- Insurance
- Software and subscriptions
- Marketing and advertising
- Professional fees (legal, accounting)
- Vehicle expenses
- Travel and meals
- Office supplies
- Depreciation
What to watch for: a category called "Miscellaneous" or "Other Expenses" that's larger than 5% of total expenses. That means transactions are being dumped into a catch-all instead of categorized properly.
Reading Net Income
Net Income is what's left after everything. As a percentage of revenue (your net profit margin), industry-typical ranges:
- Most small businesses — 5–15%
- Service businesses with low overhead — 15–25%
- Restaurants — 3–10%
- Construction — 5–10%
- Retail — 2–8%
If your net margin is negative or very low, work backward through the P&L. Is gross margin in the normal range? If yes, your operating expenses are too high relative to revenue. If no, fix gross margin first.
The three patterns to watch for
1. Revenue up, gross margin down
You're growing, but each dollar of revenue is producing less profit. Either pricing is slipping, costs are rising faster than revenue, or you're chasing low-margin work to drive top-line numbers. This is the most common warning sign in a growing business.
2. Stable revenue, expenses up
Net income is shrinking because operating expenses are creeping up while sales aren't. Software subscriptions, contractor costs, and "small recurring expenses" are usually the culprits.
3. Big swings month to month
If your P&L has wildly different numbers from one month to the next, look for: prepaid expenses being recognized all at once, annual insurance hitting in one month, inventory adjustments being applied to a single month, or revenue recognition issues. Real businesses don't usually have that kind of volatility — usually it's a reporting artifact.
Comparing P&Ls over time
A P&L by itself tells you what happened. A P&L compared to prior periods tells you what's changing. Pull these comparisons routinely:
- This month vs. last month
- This month vs. same month last year
- Year-to-date vs. year-to-date last year
- This year vs. budget (if you have one)
Most accounting software produces these comparative reports with a few clicks. The columns next to your current numbers turn the P&L from a static snapshot into a story.
What a clean P&L looks like
You'll know your P&L is in good shape when:
- Revenue is broken into 2–5 meaningful categories
- COGS is clearly separated from operating expenses
- Gross profit and gross margin % are visible
- Operating expenses are in 10–20 categories that make sense for your business
- No category is more than ~30% of total expenses (except sometimes payroll)
- "Uncategorized," "Miscellaneous," and "Ask My Accountant" categories are empty or near-zero
- You can read it and understand what your business did
Frequently asked questions
Accrual gives you better management information; cash matters for tax planning. Most accounting software lets you toggle between the two. See our cash vs. accrual guide for the longer answer.
In most accounting contexts, "revenue" and "income" mean the same thing — money your business earned from selling its products or services. "Net income" is a different thing entirely — it's the bottom line, what's left after expenses.
Three common reasons: customers haven't paid yet (accounts receivable is high), you've made principal payments on a loan (which isn't an expense and isn't on the P&L), or you've paid for things that get expensed over time (like prepaid insurance). The P&L and bank account routinely disagree.
Monthly at minimum. Weekly is reasonable for businesses with high transaction volume or thin margins. Daily is usually too noisy — there's just not enough data in one day to mean anything.
How we help
Part of our monthly bookkeeping service is producing P&L reports that are actually readable — categorized properly, compared to prior periods, with the trends visible at a glance. If your current P&L is hard to make sense of, that's almost always a bookkeeping setup issue, not a you problem.