Most owners treat a price increase as a gamble. It is not. It is arithmetic, and the arithmetic usually favours the business. The fear is that customers walk. The reality is that you can lose a surprising share of them and still earn more, as long as you know the one number that decides where the line sits.
Why this decision feels harder than it is
Every price increase carries two risks at the same time. Raise too little and rising costs quietly eat your margin. Raise too much and you lose volume you cannot easily win back. Both are real, so most owners freeze and do neither.
Standing still is not neutral. The National Living Wage rose 4.1% to £12.71 an hour in April 2026, while consumer price inflation sat at just 2.8% in the year to April. Wage and supplier costs are climbing faster than the general price level you hide behind. Hold your prices flat and your margin shrinks every month by default. The question is not whether to move, but by how much and who you can afford to lose.
The number that decides it
The figure that matters is your contribution margin: the share of each sale left after the variable costs of delivering it, such as materials, subcontractors, and card fees. If you sell something for £100 and it costs £60 to deliver, your contribution margin is 40%.
Now the part most owners never calculate. The maximum volume you can lose after a price rise and still earn the same total is: price increase divided by (contribution margin plus price increase).
Raise prices 10% on a 40% margin and the sum is 10 / (40 + 10), which is 20%. You could lose one customer in five and be no worse off. Lose fewer than that and you are ahead, on less work.
A worked example
Take Meridian, an illustrative 14-person commercial cleaning firm in Leeds turning over £1.1 million. Its average contract bills £2,000 a month at a 35% contribution margin. Costs have risen, so the owner models a 7% increase, taking the typical contract to £2,140.
The break-even maths: 7 / (35 + 7), which is 16.7%. Meridian can lose one contract in six and still bank the same total contribution, while servicing fewer sites and freeing up crew time. In practice, well-communicated B2B increases of this size rarely shed more than a few percent of clients. The owner was bracing to defend every account. The numbers said the real risk was raising too little.
The lesson holds across sectors. The higher your margin, the more volume a price rise can afford to lose. A 60% margin software firm can shed almost a third of accounts on a 10% rise and stay level. A thin-margin retailer cannot, which is exactly why it must raise prices more carefully and communicate harder.
The one thing to do this week
Pick your most common product or contract. Work out its contribution margin, then run the formula for a 7% increase. You will get a single percentage: your break-even churn. Write it on a sticky note. Once you can see that you can lose, say, 15% of buyers and still come out even, the decision stops being a fear and becomes a plan. Then sequence it: raise new customers first, give existing ones notice, and grandfather your ten most valuable accounts if you want to.
FinanceMOT is built for exactly this kind of decision. A price change moves all four pillars we score, Liquidity, Profitability, Efficiency, and Solvency, and the effect shows up over months, not on the day you send the email. Tracking your financial health score across several periods tells you whether a rise actually lifted profitability or just masked a volume problem. Your accountant shows you the numbers. FinanceMOT tells you what to do about them.
