How to start a construction business in the UK: a building company guide

You've spent years on someone else's jobs. You've watched how your gaffer prices work, you've seen what the customer pays, and at some point you've thought: I could do this myself. Plenty of good builders have that exact thought. The ones who make it are usually the ones who take the business side as seriously as the brickwork.

This guide is how to start a construction business in the UK, step by step: skills and cards, sole trader or limited company, the tax quirks only builders get, insurance, pricing and your first customers. Every legal and tax point is checked against gov.uk, HMRC and the HSE as of October 2026, and linked.

One thing up front: I'm not a builder, I'm the marketing side. So on the regulations I've stuck to what the official sources say, and where the answer depends on your circumstances, I'll point you to an accountant rather than guess.

First, decide what kind of building company you're starting

"Building company" covers a lot of ground. A two-person outfit doing extensions around Rotherham and a firm putting up six houses on a plot are barely the same business. Pick your lane first, because it changes your insurance, your tax setup, the cash you need and the customers you go after.

• Labour-only subcontracting. You work for other builders and they supply the materials. Lowest risk and lowest cash need, but you're under CIS and someone else owns the customer.
• Small works and repairs. Garden walls, repointing, small alterations. Quick jobs, steady cash.
• Extensions, loft conversions and renovations. Where most small building companies want to end up. Bigger tickets, bigger risks, and you're managing other trades.
• New homes. A different business altogether, which I come back to further down.

If you want to start a small construction business in the UK with the least risk, start near the top of that list and work down as your cash and reputation grow.

Do you need qualifications to start a building company?

There's no licence to be a builder in the UK. Nobody checks your certificates before you buy a van and paint a name on it, which is exactly why customers are wary of builders, and why proof matters so much once you're trading.

The law does expect competence, though. Since 1 October 2023 the Building Regulations in England have included dutyholder and competence rules (Part 2A): anyone carrying out building work must have the skills, knowledge, experience and behaviours to do it to the regulations, and must plan, manage and monitor the work. Where you're the only contractor, you take the principal contractor role. Most councils' building control teams publish a plain-English guide.

What helps in practice:

• A CSCS card if you'll work on commercial sites or for main contractors. It isn't a legal requirement, but without the right card you can be refused entry to site. You need to have passed the CITB Health, Safety and Environment test within the last two years, and the card application fee is £36 (CSCS).
• An NVQ in your trade, which also decides which CSCS card you can apply for.
• Site supervision training if you'll run jobs with other trades on them. CITB's SSSTS and SMSTS courses are the well-known ones.

How to start a building company: sole trader or limited company?

This is the first proper decision and the one people agonise over most. Both are fine. Lots of builders start as sole traders and move to a limited company once the profits justify the extra admin.

As a sole trader you must register for Self Assessment once you earn more than £1,000 in a tax year, and the deadline is 5 October after the end of the tax year you started in (gov.uk). Don't leave it until September. Registering late can mean a penalty.

Making Tax Digital for Income Tax is live now as well. As of October 2026, sole traders with qualifying income over £50,000 have had to use it since 6 April 2026, and the threshold drops to £30,000 from April 2027 and £20,000 from April 2028 (HMRC). Qualifying income means turnover before expenses, not profit. Builders turn over a lot of money in materials, so a builder clearing £25,000 can easily be over £50,000 turnover. Pick your accounting software early and keep digital records from day one.

If you go limited, register for Corporation Tax within three months of starting to trade, and register as an employer with HMRC before your first payday if you'll pay yourself a salary, even if you're the only director (gov.uk). How you pay yourself, salary or dividends or a mix, is exactly the kind of decision to make with an accountant, because the right answer depends on your whole situation.

CIS and VAT: the two tax bits that are different for builders

The Construction Industry Scheme

If you do work for another builder or contractor, you're a subcontractor under CIS. The contractor takes tax off your payments before you get them and passes it to HMRC: 20% if you're registered, 30% if you're not (gov.uk). So register. There's no sense giving away an extra 10% of every invoice and waiting for your tax return to sort it out.

Once you pay subcontractors yourself, you're a contractor too: register as one, check each sub with HMRC, make the deductions and send monthly returns. Established firms can apply for gross payment status (no deductions at all), but there are tests to pass, so raise it with your accountant once you've some trading history.

Work you do directly for homeowners sits outside CIS. A householder having an extension built isn't a contractor.

VAT

As of October 2026, you must register for VAT once your taxable turnover goes over £90,000 in any rolling 12 months (gov.uk). Rolling, not tax year. Builders can get there faster than they expect, because the materials you supply as part of a job count towards turnover.

Two building quirks. Under the VAT domestic reverse charge, when a VAT-registered sub does CIS work for a VAT-registered contractor, the contractor accounts for the VAT instead (HMRC guidance). It doesn't apply to work for homeowners. And not all building work is charged at 20%: building a new home is generally zero-rated, and some conversions are charged at 5%. If you're heading anywhere near new builds or conversions, sit down with an accountant before you quote, not after.

Insurance for a small construction business

Insurance is the bit everyone buys too cheaply and only reads properly after something's gone wrong. What to look at:

• Public liability. Not a legal requirement, but no sensible customer or main contractor will let you start without it. It covers injury to other people and damage to their property: a dropped scaffold board, a crack in next door's wall, a hole through a ceiling.
• Employers' liability. A legal requirement as soon as you employ anyone, with at least £5 million of cover. You can be fined £2,500 for every day you're not properly insured (gov.uk). The exemptions are narrow, and casual labourers can count as employees, so ask your broker rather than assume.
• Contract works. Covers the work itself, and often the materials on site, until handover. If a half-built extension gets wrecked by a storm or a fire, this is what pays to put it right.
• Tools and plant. Read the small print on overnight van storage.
• Professional indemnity if you'll do any design yourself.
• Van insurance with business use. A policy for social and commuting use won't cover you driving between jobs with a van full of kit.

The rules you'll meet on your first proper job

CDM on homeowner jobs

The Construction (Design and Management) Regulations 2015 apply to domestic jobs too. When you're the only contractor, the client's legal duties pass to you on top of your own. With more than one contractor, they pass to the principal contractor (HSE). In practice: plan the job safely, write a construction phase plan proportionate to the job, and get the site basics right.

Building control

Most extensions and structural alterations need building regulations approval, through your council or a registered building control approver. Since the 2023 changes, the principal contractor also signs a completion declaration with the client, and building control won't issue a completion certificate without it. Get to know your local building control surveyors early. They're far more useful as allies than as the people who find your mistakes.

Party walls

If the job is on or near a shared wall or boundary, the Party Wall Act may apply, and it's the homeowner who has to tell the neighbours (gov.uk). Spotting it at the quote stage makes you look like the professional in the room and stops your start date sliding.

Waste

Rubble, old kitchens, bathroom suites, fence panels: that's construction and demolition waste, and in England carrying it means registering as an upper tier waste carrier, even when the waste comes from your own job. As of October 2026 registration costs £191.02 and lasts three years, with renewal at £130.25 (gov.uk). Put your registration number on your quotes and your website. Homeowners have a legal duty to check who takes their waste away, and the careful ones do.

Cancellation rights

Agree a job in the customer's home and they usually get 14 days to cancel under the Consumer Contracts Regulations, which you must tell them in writing. Leave it out and the window can stretch to 12 months. If they want you to start sooner, get that request in writing. A decent quote template sorts this once.

How to start a construction business with no money

"No money" usually means "not much", and that's fine. Plenty of building companies started with a used van, a set of tools and a phone. Ways to keep the start-up cost down:

• Start labour-only. Subbing for other builders means no materials to fund and no customers to chase while you build a name. Just register for CIS first.
• Hire, don't buy. Mixers, breakers, towers, the big saw: hire them until you use them often enough that owning works out cheaper.
• Never fund the customer's job. On bigger domestic jobs, staged payments tied to clear milestones mean you're not buying someone's roof timbers out of your own pocket. Put the stages in the quote.
• Open trade accounts. Merchant credit gives you breathing room between buying materials and getting paid. Pay on time and the limit grows with you.
• Skip the yard and the new van. A tidy used van with decent racking does more for you in year one than a new one on finance. Keep it clean, too: to a homeowner it's your shop front.

What you can't skimp on: insurance, registrations and a written quote for every job.

Starting a home building company

If by building company you mean building new homes to sell, that's property development. You're buying land, getting planning permission, raising development finance and selling the house, as well as building it. The building is often the most predictable part.

One thing catches new developers out. Most buyers need a mortgage, and lenders generally want a new home to come with a structural warranty from an approved provider (NHBC is the best known) or a professional consultant's certificate. Talk to a warranty provider before you buy a plot, because they'll want to register you and inspect the build as it goes up. The well-trodden route is extensions and renovations first, building up cash and contacts, then one plot at a time.

Pricing building work so you actually make money

Most new builders underprice. Not because they're bad at maths, but because they price against their old day rate and forget the business now pays for everything their employer used to.

Here's a simple way to find your floor. The numbers are made up, so swap in your own:

• You want to earn £40,000 a year before tax.
• Your running costs (van, fuel, insurance, phone, accountant, tools, website) come to £12,000 a year.
• There are 260 weekdays a year. Take off 8 bank holidays and 20 days' holiday and you've got 232. Lose a fifth of those to quoting, weather, gaps between jobs and admin, and you're left with about 186 paid days.

£52,000 divided by 186 days is about £280 a day, before materials and before any profit for the business itself. If your price comes out below that, you're paying to go to work.

On top of that goes materials (with a markup for the time spent ordering, collecting and taking stuff back), a contingency for what you find when you open things up, and a margin. Put it all in a written quote: what's included, what isn't, the payment stages, and how extras get priced. A lot of building disputes start with the words "I assumed that was included".

Getting your first customers

This is the bit I actually know. I've spent over ten years in SEO and grown my own websites to 50,000+ visits a month, so here's what I'd set up before the first job, in this order.

A name that works on a van and on Google

Your name goes on your van, your quotes, your web address and your Google profile, so it needs to work in all four places. I've written a separate guide to building company names and trade business name ideas, including the checks to run before you pay a signwriter.

A Google Business Profile

This is the free listing that shows on the map when someone searches "builders near me" or "extension builder Doncaster", and it's often a new building company's quickest route to enquiries from strangers. I've walked through it in how to set up a Google Business Profile. Pick your main category carefully, list the work you actually want, and add photos from every job.

A simple website

Building work is expensive and customers are nervous, so they check you out before they ring. A plain website with your services, areas, photos of real jobs and registrations does a lot of the convincing for you. If you're not sure you need one yet, here's my honest answer to do I need a website. If you do, here's how I approach websites for builders, and websites for construction companies if you're going after bigger commercial work.

Reviews from day one

Every finished job is a chance for a Google review. Ask while you're packing up, and text the link so it takes thirty seconds. In my opinion a handful of genuine reviews with photos will win you more extensions than any advert. Never buy them, though: fake reviews have been illegal in the UK since April 2025.

Then, later, SEO

Once the basics are in and you've got jobs behind you, think about ranking for searches like "builders in Sheffield". It's a longer game, and I'd rather you didn't pay anyone for it before the profile, website and reviews are sorted. When you're ready, this is how I do SEO for builders and SEO for construction companies.

Questions people ask about starting a building company

How much does it cost to start a construction business?

Anything from a few thousand pounds (a used van, hand tools, insurance and registrations, working labour-only) to tens of thousands if you're buying plant and funding materials. The fixed costs are small: £100 for a limited company online, nothing for CIS, £191.02 for upper tier waste carrier registration as of October 2026. Insurance, van and tools are the big numbers and vary too much to guess. Get three quotes for each.

Can I start a building company without qualifications?

Legally, yes: there's no licence to be a builder in the UK. But the Building Regulations expect anyone doing building work to be competent, main contractors will want the right CSCS card, and plenty of customers check. Qualifications and trade memberships end up being some of your best marketing.

Do I need to register for VAT straight away?

Only once taxable turnover passes £90,000 in a rolling 12 months (as of October 2026). Registering voluntarily can suit you if your customers are mostly VAT-registered businesses. Homeowners can't reclaim VAT, so for domestic work it mostly makes you dearer.

Where I come in

I can't lay a brick. What I can do is make sure people searching for a builder in your area find you and ring you. I build websites for trades personally: £497 one-off, no VAT and no deposit, and you see your homepage design within 24 hours of the set-up call, before you pay anything. Hosting and your web address are £20 a month on top, paid by you, so you own the lot.

If you're starting out and want to see what yours could look like, get your free website mockup. And if I think you don't need a website yet, I'll tell you.