Every trades business has to decide how to charge. Some quote a fixed price for each job. Others charge an hourly rate plus parts. Many do a mix without ever really deciding why. The choice affects your profit, your cash flow, how customers see you and even how hard your technicians work.
This guide compares flat rate vs time and materials pricing for trades, with worked examples, and explains how to decide which model suits which jobs. If you have not yet worked out your true hourly costs, start with our guide to pricing service jobs, because both models depend on them.
What Is Time and Materials Pricing?
With time and materials (often shortened to T&M), the customer pays for the hours worked at an agreed rate, plus the cost of materials and parts, usually with a markup. Many businesses also add a call-out fee or minimum charge.
Example: A plumber charges £65 per hour plus parts at cost plus 20%. A tap replacement takes 1.5 hours and uses £40 of parts. The customer pays £97.50 labour plus £48 parts, so £145.50 plus any call-out fee.
What Is Flat-Rate Pricing?
With flat-rate pricing, the customer is quoted a fixed price for a defined task before the work starts, regardless of how long it takes. The price is built from the average time, materials, overhead and target profit for that type of job, and often comes from a price book.
Example: The same plumber charges a flat £159 to replace a standard tap, including parts and labour. If it takes 1 hour, the business does well. If it takes 2.5 hours because of seized fittings, the business absorbs the extra time unless the scope changes.
The Pros and Cons Side by Side
| Time and materials | Flat rate | |
|---|---|---|
| Price certainty for customer | Low | High |
| Risk of overruns | Customer carries it | Business carries it |
| Reward for efficiency | None (faster work earns less) | High (faster work earns more) |
| Effort to set up | Low | Higher (needs price book and data) |
| Disputes about time | Common | Rare |
| Suits | Unpredictable work, diagnosis, larger projects with changing scope | Repeatable, well-defined tasks |
Why Many Trades Move Towards Flat Rate
Customers increasingly expect a price before work starts. Flat-rate pricing removes the awkward conversation about why a job took three hours instead of two, and it makes your business easier to say yes to.
It also changes incentives inside the business. On T&M, a technician who works faster brings in less revenue per job. On flat rate, faster and better work earns more per hour, which rewards skill, good van stock and good preparation. Our guide to revenue per technician shows how to measure this.
Finally, flat rate can protect margin when it is built properly. A well-designed price includes your loaded labour cost, a share of overhead and a target profit, rather than relying on a headline hourly rate that customers compare with the cheapest competitor.
Where Time and Materials Still Makes Sense
Flat rate is not always the right answer. T&M is usually safer when:
- The problem has not been diagnosed yet. Charge for diagnosis on time, then quote a flat price for the fix.
- The scope is genuinely unknown, such as tracing an intermittent electrical fault or working in an old property with hidden problems.
- The job is large and likely to change, such as renovation work where the customer keeps adding requests.
- Commercial clients require it under a contract or framework agreement.
In these cases, protect both sides with clear terms: an estimate range, a point at which you will stop and check in, and written approval for anything extra.
A Worked Example: Same Job, Different Outcomes
Let us compare a boiler repair priced both ways. Assume the business has a loaded labour cost of £40 per hour and wants at least a 45% gross margin.
Time and materials: £70 per hour, parts at cost plus 25%.
Flat rate: £295 for this specific repair, including a £90 part.
| Scenario | Hours | T&M price | T&M gross profit | Flat price | Flat gross profit |
|---|---|---|---|---|---|
| Quick job | 1.5 | £105 + £112.50 = £217.50 | £217.50 − £60 − £90 = £67.50 (31%) | £295 | £295 − £60 − £90 = £145 (49%) |
| Typical job | 2 | £140 + £112.50 = £252.50 | £252.50 − £80 − £90 = £82.50 (33%) | £295 | £295 − £80 − £90 = £125 (42%) |
| Difficult job | 3.5 | £245 + £112.50 = £357.50 | £357.50 − £140 − £90 = £127.50 (36%) | £295 | £295 − £140 − £90 = £65 (22%) |
A few things stand out:
- On flat rate, efficient work is much more profitable.
- On flat rate, difficult jobs hurt, which is why your price must be based on realistic average times and clear scope.
- On T&M, the business is protected on difficult jobs but earns less on quick ones, and the customer pays very different prices for the same repair.
To measure this properly across your business, track gross profit per job for each job type over a few months.
How to Build Flat-Rate Prices
- List your most common jobs. Start with the 20 to 30 jobs that make up most of your work.
- Find the real average time for each from your job records, including travel and setup.
- Add typical materials at your purchase cost.
- Apply your loaded hourly cost and a share of overhead.
- Set a price that hits your target margin on the average job, with enough buffer for harder ones.
- Define the scope clearly so customers know what is included and what would change the price.
- Review prices every six to twelve months, or sooner if material costs move.
Many field service platforms include price books so technicians can quote consistently on site.
The Hybrid Approach Most Businesses End Up Using
In practice, many successful trades use both:
- Diagnosis or survey charged at a fixed fee or on time.
- Common repairs and installs at flat rates from a price book.
- Large or unpredictable projects on T&M with an estimate range, or broken into fixed-price stages.
The key is that each choice is deliberate. If you are not sure which approach is improving your results, look at your gross margin by job type.
Frequently Asked Questions
Do customers prefer flat-rate pricing?
Many homeowners do, because they know the cost before agreeing to the work. It also reduces arguments about time spent.
Is flat-rate pricing more profitable?
It can be, if prices are based on accurate average times and costs and your team works efficiently. Badly calculated flat rates can lose money on difficult jobs.
How do I handle unexpected problems on a flat-rate job?
Define the scope in writing. If you find something outside that scope, stop, explain it to the customer and agree a revised price before continuing.
Should I show my hourly rate on my website?
That is a business choice. Showing an hourly rate invites comparison with cheaper competitors. Showing “from” prices for common jobs gives customers guidance without reducing the conversation to hourly rates.
Conclusion
Neither model is right for every job. Flat-rate pricing gives customers certainty and rewards efficient, skilled work, but it needs good data and clear scope. Time and materials protects you when the job is unpredictable, but it can cap your earnings and create disputes. Most trades businesses do best with a deliberate mix: flat rates for repeatable work, time-based charges for diagnosis and uncertain projects, and regular reviews of the numbers behind both.
