Reading your monthly profit and loss: the three numbers most sole traders ignore

Most UK sole traders judge how their business is doing by looking at their bank balance. End of the month, balance is up, things are good. End of the month, balance is down, time to worry.

The bank balance is a poor proxy for business health. It mixes income, expenses, tax owed but not yet paid, and one-off purchases into a single number that can rise in an unprofitable month (because you've put off paying bills) and fall in a healthy one (because you bought equipment). It tells you nothing about which services are actually profitable.

A monthly profit and loss statement (P&L) is the alternative. It takes 20 minutes to update if your invoices and expenses are already tracked, and it reveals three numbers that most self-employed people never look at directly. Each one changes how you make decisions about the business.

This post is about those three numbers, what each one tells you, and what to do with the information.

Total revenue minus the direct cost of delivering each service, expressed as a percentage of revenue. Done at the service-type level, not the business level.

For a tattoo artist, this means working out the gross margin on a custom piece versus a flash piece versus a touch-up. The direct costs include the time spent (your hourly rate × hours), ink and supplies used, machine wear allocated, and a share of the studio chair time if you rent space.

A typical breakdown might show that custom pieces have a 70 per cent gross margin, flash work has a 60 per cent margin, and touch-ups have a 35 per cent margin. The numbers vary by artist, but the principle is the same: different services have different margins, and the differences are usually larger than artists assume.

What this changes: how you allocate your week. If touch-ups are 35 per cent margin and custom is 70 per cent margin, the marginal hour spent on custom work is twice as profitable as the marginal hour on touch-ups. Some businesses can't simply pivot to higher-margin work (touch-ups have client-relationship value beyond the immediate margin), but the margin number tells you the trade-off you're making.

Most sole traders, in any trade, find that one or two services they offer have margins meaningfully lower than they assumed. Those are the services to either reprice, restructure, or stop offering.

Total fixed monthly costs (rent, insurance, software subscriptions, professional fees, equipment finance) divided by total monthly revenue, expressed as a percentage. This tells you how much of every pound you earn goes to keeping the lights on before you've covered variable costs or paid yourself.

For a tattoo artist renting a studio chair, fixed costs might run around £400/month: chair rent £300, insurance £40, professional memberships £20, booking and accounting software £25, phone and internet £15. At £4,000 monthly revenue, fixed costs sit at 10 per cent. At £2,500 in a quiet month they jump to 16 per cent. At £6,000 they fall under 7 per cent. Fixed costs don't drop when work is slow, so this number gives you a floor — the minimum monthly revenue at which the business breaks even on fixed costs alone — and a way to model whether moving from a chair rental to your own studio (where fixed costs might double or triple) is something your typical revenue can support.

How much money actually reaches your personal bank account compared to how much profit the business records. These two should be close to each other for a sole trader (you keep the profit minus tax) and often aren't, because tax owed isn't always set aside and personal drawings often happen ad-hoc. A business that records £4,000 of profit in a month but only retains £1,500 in cash has £2,500 going somewhere — sometimes legitimate (paying down equipment finance, building inventory), sometimes not. Without watching this number, the gap between profit and cash quietly grows.

What this changes: you set yourself a salary. The right approach for most sole traders is to pay yourself a fixed amount monthly based on what the business can sustainably afford, let the business retain the rest, and reconcile quarterly. This separates personal cashflow from business cashflow and removes the constant low-grade anxiety of "do I have enough this month?" For a tattoo artist averaging £4,000/month profit after expenses, paying themselves £2,500/month and retaining £1,500 in the business is a more sustainable structure than drawing whatever happens to be in the account.

The form itself is straightforward. Three sections.

Income at the top. Total revenue for the month, broken down by service type if you offer more than one. For a tattoo artist that might be: custom work, flash work, touch-ups, retail (if you sell aftercare products or merchandise).

Expenses in the middle, by category. For a tattoo artist that might be: chair rent or studio costs, ink and supplies, machine maintenance, training, insurance, software, professional fees, marketing, accountant.

Net profit at the bottom. Income minus expenses. The number that matters.

Optionally a fourth section: tax allocation. A simple line that records how much of the net profit is being set aside for income tax and Class 4 NI (typically 25–30 per cent of net profit, depending on your earnings band). This isn't an expense, but tracking it separately makes the take-home calculation honest.

The whole P&L for a single sole trader fits on one page or one spreadsheet tab. Updated monthly from your income tracker and expense tracker, it takes about 20 minutes.

The P&L is the most-skipped piece of financial admin for UK sole traders, mostly for predictable reasons. It feels boring, it surfaces uncomfortable truths (the first time a tattoo artist sees their touch-up margin is 35 per cent, denial is more common than action), and it depends on the underlying records being in shape. So it gets postponed until the records are sorted, which never quite happens.

The pragmatic response is to start small. A basic monthly P&L built from imperfect records beats no P&L from clean ones. Get the structure in place, populate it from what you have, and refine the inputs over the next few months. The artists, plumbers and salon owners who run their businesses well are almost universally the ones who look at their P&L every month. The ones who don't are usually the ones still wondering, three years in, why a business that feels busy doesn't feel profitable.

LaunchKit makes a niche-specific Financial Forms Bundle that includes a monthly profit and loss template tailored to each trade. Available in three tiers on Etsy and yourlaunchkit.co.uk: Standard at £11.99, Custom at £13.99, Premium at £19.99. Premium adds editable Word versions for full customisation. One-time purchase.

If you'd rather build your own P&L spreadsheet, the structure above gives you the template. The bundle just saves the setup time.

This article is general business guidance, not financial advice. For your specific situation, consult a qualified accountant.

For personal trainers, connect the monthly profit-and-loss review to session blocks, retained clients, equipment costs and room-hire decisions.

• Personal Trainers templates and tools
• Personal Trainers financial forms bundle