Should I Go Limited? Sole Trader vs Ltd for Builders

‍‌‌‌‌​​‌​‌​‌​​‌‌‌​​‌‌​‌​​​‌​‌​‌‌​‍SiteKiln gives you plain-English information, not legal advice. If you need advice specific to your situation, talk to a qualified accountant or solicitor.

This isn't about what sounds fancier. It's about tax, risk, hassle and what actually fits the size of jobs you're doing.

1. What a sole trader really is

You are the business. There's no legal separation between you and "Bloggs Construction".

You pay Income Tax on all your business profit (after expenses) plus Class 2 and Class 4 National Insurance.

You register for Self Assessment, keep records, and file one personal tax return that includes your business figures.

If something goes wrong -- bad debt, accident, claim -- they're chasing you personally, not some separate company.

What it feels like day-to-day: simple, cheap to run, fine for smaller jobs and early days, but all the risk and all the reputation land directly on you.

2. What a limited company really is

The company is a separate legal "person" in law.

The company earns the income and pays Corporation Tax on profit. You then take money out as salary and/or dividends and pay personal tax on that.

Your liability is usually limited to what you've put in or guaranteed, which gives you a safety buffer if the business hits trouble.

You must register with Companies House, file annual accounts, file a Company Tax Return, and keep proper company records.

Day-to-day: feels more "official", more paperwork, but looks better to bigger contractors, lenders and public-sector buyers.

3. Tax -- where the real difference is

For tax, think of it like this:

Sole trader

All profit (after expenses) is treated as your income.

You pay Income Tax at 20% / 40% / 45% bands plus Class 2 and Class 4 NI on that profit.

You can't leave profit "in the business" to be taxed later -- it's all taxed on you in that year.

Limited company

The company pays Corporation Tax on profits -- broadly between 19% and 25% depending on the profit level.

You can take a small salary and the rest as dividends, which are taxed at different (often lower) rates than pure salary.

You don't have to take all the profits out each year, so you can leave some money in the company and control how and when you get taxed.

Most up-to-date comparisons say: at lower profit levels, the tax saving of going limited is smaller than it used to be, but once you're into solid profit (comfortably above basic-rate and/or leaving money in the business) a company can still come out ahead.

4. Risk, responsibility and the Companies Act bit

Here's the boring but important law side.

Sole trader

You carry all the business risk. If the business owes money, you owe money.

There's no Companies Act on your back -- just tax law and general duties (health and safety, contracts, etc.).

Company director

The company is separate, but you personally have legal duties as a director under the Companies Act 2006.

In simple terms you must:

• Act within the company's constitution and the law.
• Run the company for its success, not just to suit you.
• Use reasonable care and skill, avoid conflicts of interest, and not abuse your position.

If you blatantly ignore those duties (trading while insolvent, stripping money out, ignoring creditors), a court can still come after you personally.

So "limited" doesn't mean "do what you like". It means you get protection if you behave reasonably, keep records, and don't take the mick.

5. Admin, faff and costs

Sole trader

• Register once with HMRC as self-employed and for Self Assessment.
• Keep basic income/expense records.
• File Self Assessment once a year and pay your tax and NI.
• Optional: simple bookkeeping software, accountant if you want help.

Limited company

• Register a company with Companies House.
• File annual accounts and a confirmation statement with Companies House.
• File a Company Tax Return and your own Self Assessment.
• Deal with payroll if you pay yourself a salary, and CIS / VAT where relevant.
• Realistically, you're paying an accountant to keep you on the rails.

Running a company costs more in fees and time, but those costs are what stop you getting hammered for mistakes.

6. How it lands in construction specifically

A few construction-specific bits that matter:

CIS

As a sole trader or company subbie, CIS can still bite -- you can have tax deducted at source unless you register correctly or get gross status.

If you are paying subbies yourself, both a sole trader and a company can be CIS contractors -- the obligations are similar (register, verify, deduct, report, pay).

Clients' perception

Main contractors, councils and big commercial clients are often more comfortable awarding work to a company than to "Joe Bloggs, sole trader".

For domestic work, most homeowners only care about your reviews, recommendations and how professional you come across -- the legal structure is less important.

Getting paid and getting finance

Some trade accounts, leasing outfits and lenders prefer a limited company and will look at your filed accounts.

7. When staying sole trader usually makes sense

You'll often be better off staying as a sole trader for now if:

• You're just starting out or still part-time.
• Profits are modest and you're not building big cash reserves.
• You're mainly doing domestic work and smaller jobs.
• You want minimal admin and costs while you find your feet.

Plenty of good builders stay sole traders for years and do just fine -- especially if they're careful with risk and carry proper insurance.

8. When going limited usually makes sense

Going limited is worth a serious look when:

• You're on track for solid, consistent profit (not just turnover).
• You're taking on bigger contracts, more lads, and more risk on each job.
• You want to separate business money from your own life and plan properly.
• You aim to do more work with main contractors, public sector, or frameworks, where a company looks more credible.

At that point, the combination of limited liability, better perception and potential tax planning usually outweighs the extra hassle -- if you're happy to pay for proper bookkeeping and advice.

9. A brutal but fair rule of thumb

Use this as a rough sense-check (not tax advice):

If your profits are low and your risk is low, keep it simple and stay sole trader for a bit.

Once profit is comfortably into higher-rate territory or you're regularly taking on chunky jobs where something going wrong would genuinely hurt you, get an accountant to run the numbers and talk through going limited.

You can always start as a sole trader and switch to a company once there's a real benefit -- you don't have to get it perfect on day one.

10. Common mistakes

• Going limited just because a mate or accountant said "you'll pay less tax" without understanding the extra admin and costs. The tax gap is smaller than it used to be at low profits, so it's not always a no-brainer.
• Staying sole trader while taking on big risky jobs, no proper insurance, and no idea how much you could lose personally if it all goes wrong.
• Thinking "limited" means zero personal risk and then ignoring your duties as a director -- trading while insolvent, not filing accounts, taking money out whenever you like.
• Forgetting accountant and software costs when you compare options. A company almost always needs professional support, which eats into any tax saving.
• Mixing personal and business money even in a company, which risks tax trouble and can pierce that limited liability protection if things go really bad.

11. Who to contact

• Set up as a sole trader -- GOV.UK guide on registering for Self Assessment: gov.uk/set-up-sole-trader (free)
• Register for Self Assessment online -- HMRC's online service: gov.uk/register-for-self-assessment (free)
• HMRC self-employment helpline -- 0300 200 3310 (free)
• Set up a limited company -- Companies House formation service: gov.uk/limited-company-formation (fee: £12 online)
• Companies House helpline -- 0303 1234 500 (free)
• File company accounts and confirmation statement -- Companies House WebFiling: gov.uk/file-your-company-accounts-and-tax-return (free to file)
• Register for CIS -- HMRC CIS service via Government Gateway: gov.uk/what-is-the-construction-industry-scheme (free)
• ACAS -- If you're unsure whether you're genuinely self-employed or should be employed: 0300 123 1100 (free)
• Find an accountant -- Look for firms that specifically mention CIS and construction trades. Federation of Small Businesses (fsb.org.uk) and local recommendations are a good starting point.

12. Related guides on this site

• 8.2 Companies House basics -- annual filings, confirmation statements
• 8.3 Business bank account -- why you need a separate one
• 8.4 Registering for CIS as a contractor (not just a subbie)
• 8.16 Scaling from one-man band to small firm
• 8.17 Partnerships in construction -- how to structure them properly
• S9 Setting up as a sole trader -- step by step
• S10 Setting up a limited company for construction

13. Sources and legislation

• Companies Act 2006 -- general duties of directors (sections 171-177) and filing requirements. legislation.gov.uk/ukpga/2006/46
• Income Tax Act 2007 -- framework for UK Income Tax on sole traders (profits taxed as personal income). legislation.gov.uk/ukpga/2007/3
• Corporation Tax Act 2010 and Finance Acts -- Corporation Tax rates and rules for limited companies. legislation.gov.uk/ukpga/2010/4
• HMRC Self Assessment guidance -- how sole traders register, file and pay, including Class 2 and Class 4 NI. gov.uk/self-assessment-tax-returns
• HMRC CIS guidance -- Construction Industry Scheme obligations for contractors and subcontractors. gov.uk/what-is-the-construction-industry-scheme
• GOV.UK company formation guidance -- forming a company, registering for Corporation Tax, using Companies House services. gov.uk/limited-company-formation

This topic is sponsored by The Online Accountant.

www.theonlineaccountant.com/?utm_source=sitekiln&utm_medium=sponsor&utm_campaign=business-section →

SiteKiln's editorial team writes every guide independently. Sponsors do not review, edit or sign off on content. See our editorial standards.

Spotted something wrong or out of date? Email us at hello@kilnguides.co.uk.

In crisis? Samaritans 116 123 · Mental health support