Should UK trades mark up materials and charge for merchant runs? Absolutely. Supplying materials at cost means you take on product liability, warranty callbacks, and credit risks for zero return. Standard UK trade markups sit between 15% and 25%, and travel to collection counters should always be billed as working time.
Every week, thousands of self-employed tradespeople across the country turn up at the trade counter at 7:30 AM, load up heavy gear, battle through morning traffic to site, and hand over the final invoice with zero markup on the items they supplied.
The reasoning usually sounds reasonable enough: “I make my living on my labour; I pass the trade discount on so the customer gets a fair deal.”
In reality, passing materials on at invoice cost is one of the quickest ways to bleed money. When you order, collect, finance, and guarantee building materials, you are not doing a friendly favour—you are providing a specialised procurement and delivery service completely unpaid.
The True Cost of Supplying Materials at Cost
When you supply materials for a customer, your responsibility does not end when you tap your card at the till. Selling parts at zero markup forces your business to absorb three serious risks:
- The Unpaid Warranty Trap: If a thermostatic valve fails or a breaker is faulty straight out of the box three months down the line, the customer calls you. You drive back out, isolate the system, return the faulty part to the merchant, and fit the replacement. If you did not put a markup on that part, that entire morning of warranty work comes straight out of your own wages.
- Financing the Customer’s Job: When you put £1,500 of supplies on your 30-day merchant account, you are acting as an interest-free bank for the client. If an invoice gets delayed or queried, your business carries that debt.
- Wastage and Transit Damage: Fittings get dropped, tiles crack during tricky cuts, and lengths of pipe get scuffed. The trade standard for material wastage is around 10% to 15%. If you do not allow for that in your pricing, you end up paying for damaged goods yourself.
The silent cost of unbilled merchant runs: If you spend forty-five minutes every Tuesday and Thursday morning queuing at trade counters, that is six full hours a month spent off the tools. Over a working year, that is well over £3,000 in unbilled working time. Most trades set their day rates assuming a clean eight hours on the tools, completely overlooking how morning trade runs, unpaid estimating, and van diesel drain their actual take-home cash.
To see what unbilled merchant trips and overheads are actually doing to your personal bank balance, run your numbers through my free day-rate and take-home pay calculator. It reveals your exact baseline break-even rate so you can quote your packages properly and stop commercial revenue loss.
Sensible Material Markups for UK Trades
Applying a markup is standard business practice across construction. Legally and commercially, you are setting a retail price for items you are supplying and guaranteeing. Typical UK trade benchmarks are:
- Standard Commodity Materials (10% to 15%): Bulk timber, cable reels, sand, cement, and standard copper fittings.
- Specialist Fixtures & Fittings (20% to 25%): Consumer units, designer sanitaryware, bespoke radiators, and smart heating controls.
- Emergency / Sourced Spares (25% to 35%): Hard-to-find boiler parts or components sourced at short notice to keep an urgent job moving.
That 20% markup is not a cheeky extra—it covers your time checking the specification, the fuel used to collect it, and the legal responsibility you take on under the Consumer Rights Act to replace it if it fails.
What to Say When a Customer Asks About Part Prices
Every now and then, a customer will pull up a DIY store website on their phone and ask why your invoice price is slightly higher than the shelf price.
Keep your answer calm, direct, and professional: “When I source the materials, that price covers hand-picking trade-grade parts, transporting them safely to your home, and covering my own labour free of charge under warranty if an item develops a fault within the first twelve months.”
If a homeowner insists on buying their own fixtures online, that is fine—as long as you agree upfront that if their cheap part arrives missing screws, gets damaged in transit, or fails in six months’ time, any visit to diagnose, strip down, or replace it is billed at your full hourly rate.
Are uncharged hours and parts margins eating your profits?
Stop guessing your rates based on what someone else charges. Factor in your real vehicle expenses, trade counter runs, and non-billable hours in seconds.
Supplying materials at cost is one of the most common causes of revenue loss in the trades. Before you price your next quote, take two minutes to check your baseline using my free UK day-rate calculator and make sure you are charging enough to protect your take-home pay.