At what income level should a plumber consider going limited company?

The break-even point varies but is typically around £40,000–£50,000 net profit per year. Below this, the tax saving from a limited company is often outweighed by the additional accountancy fees and administrative burden. Above £50,000 profit, a limited company can save a plumber £2,000–£6,000 per year in tax, depending on how profits are extracted. Get a quote from an accountant before making the switch.

Can I still work under CIS as a limited company plumber?

Yes. Limited companies can register for CIS as subcontractors. The company receives CIS deductions (at 20% of labour) and reclaims them via PAYE rather than Self Assessment. The process is more complex than for sole traders — you will need an accountant familiar with CIS for limited companies.

Is a limited company better for a plumber's liability?

In theory, yes — limited liability means your personal assets are separate from business debts. In practice, for plumbers, the main liability risk is covered by public liability insurance, which you need regardless of business structure. Many sole traders and limited companies carry the same £5m public liability policy. Limited liability is a genuine benefit if you take on large commercial contracts where financial exposure could be significant.

How much extra admin does a limited company involve for a plumber?

Significantly more than a sole trader. A limited company must file annual accounts with Companies House, file a Corporation Tax return, run PAYE payroll for your own salary, file confirmation statements, and maintain company registers. Most plumbers find they need an accountant at a cost of £1,000–£2,500 per year. As a sole trader, a basic accountant costs £300–£600 per year. The admin difference is real — factor it into any tax saving calculation.

Plumber: Sole Trader vs Limited Company UK (2026) — Which Pays Less Tax?

Sole Trader vs Limited Company: Full Comparison

Factor	Sole trader	Limited company
Setup	Register with HMRC for Self Assessment — free, 10 minutes	Register with Companies House — £50 online, takes 24 hours
Tax on profits up to £50,270	20% income tax + 6% Class 4 NI = 26% effective marginal rate	19% Corporation Tax (below £50k profit). Extract via salary + dividends
Tax on profits £50,270–£125,140	40% income tax + 2% Class 4 NI = 42% marginal rate	25% Corporation Tax above £50k. Dividend tax 10.75% at basic rate (2026)
Personal liability	Unlimited — personal assets at risk if business has debts	Limited — company debts are separate from personal assets
Annual admin	One Self Assessment tax return per year	Accounts, CT600, PAYE, confirmation statement — ongoing quarterly tasks
Accountancy cost	£300–£600/year typically	£1,000–£2,500/year typically
MTD for ITSA (from April 2026)	Quarterly digital submissions if earning over £50k	MTD for ITSA does not apply — Corporation Tax MTD timeline is later
CIS treatment	Reclaim via Self Assessment — simple and direct	Reclaim via PAYE — more complex, needs accountant
Business perception	Fine for most domestic and small commercial work	Some larger contractors prefer limited companies for subcontract work

Tax Worked Examples at Different Income Levels (2026/27)

These are simplified illustrations. Your actual position depends on your specific expenses, salary extraction strategy, and personal circumstances. Always get specific advice from an accountant before incorporating.

£35,000 profit

Sole trader tax

~£6,500 (income tax + NI after personal allowance)

Limited company total

~£6,600 (CT + income tax on salary/dividends) + £1,200 accountancy fees

Verdict: Sole trader wins — no benefit to incorporating and extra costs.

£55,000 profit

Sole trader tax

~£16,000 (higher rate income tax kicks in)

Limited company total

~£12,500 (CT + salary + dividends optimised) + £1,500 accountancy fees

Verdict: Limited company saves ~£2,000/year net of accountancy fees. Worth considering.

£90,000 profit

Sole trader tax

~£32,000 (heavy higher-rate exposure)

Limited company total

~£24,000 (CT + optimal salary/dividends) + £2,000 accountancy fees

Verdict: Limited company saves ~£6,000/year net. Clear advantage at this level.

2026 dividend tax change

The basic rate dividend tax increased to 10.75% from 6 April 2026. This has narrowed the tax advantage of a limited company versus sole trader at income levels between £50,000–£80,000. If you were considering incorporating in this income range, run the numbers again — the saving is smaller than it was in previous years.

When Does a Limited Company Make Sense for a Plumber?

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Net profit consistently above £50,000

This is the typical trigger point. Above £50k profit, the tax saving from a limited company structure usually exceeds the extra accountancy costs.

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Significant liability exposure

Large commercial contracts, development projects, or work where a single mistake could result in a substantial claim. Limited liability separates personal assets from business risk.

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You want to reinvest profits in the business

A limited company lets you leave profits in the business paying only 19% Corporation Tax, rather than withdrawing everything and paying income tax. Useful if you are building up capital for equipment or expansion.

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Subcontract work with large contractors

Some major contractors and developers prefer or require subcontractors to operate through a limited company. If this is preventing you from winning work, it may justify the switch.

When Sole Trader Is the Better Choice

For most UK plumbers, sole trader remains the right structure. You should stay as a sole trader if:

Your net profit is below £40,000–£50,000 per year
You value simplicity and hate admin
You mostly do domestic work for private homeowners
You are just starting out and building your customer base
You want to avoid the cost of a limited company accountant (£1,000–£2,500/year)

The vast majority of self-employed plumbers in the UK operate as sole traders throughout their careers — and this is entirely sensible. Focus on maximising income and claiming every allowable expense before worrying about your business structure.

Invoicing as a Sole Trader vs Limited Company

The invoicing requirements differ slightly between structures:

Requirement	Sole trader	Limited company
Business name on invoice	Personal name + trading name	Registered company name (exactly as on Companies House)
Address on invoice	Business address	Registered office address
Company number	Not required	Must include Companies House registration number
Director name	Not required	Not required on invoice (but required on letters/emails)
VAT number	If VAT-registered	If VAT-registered

TraderInvoice works for both sole traders and limited companies. Your business details — including company number if applicable — appear on every invoice automatically from your account settings.

Professional invoicing whatever your structure

TraderInvoice works for sole traders and limited companies. Voice invoice in seconds — free for up to 5/month.

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Frequently Asked Questions

At what income level should a plumber consider going limited company?: The break-even point varies but is typically around £40,000–£50,000 net profit per year. Below this, the tax saving from a limited company is often outweighed by the additional accountancy fees and administrative burden. Above £50,000 profit, a limited company can save a plumber £2,000–£6,000 per year in tax, depending on how profits are extracted. Get a quote from an accountant before making the switch.
Can I still work under CIS as a limited company plumber?: Yes. Limited companies can register for CIS as subcontractors. The company receives CIS deductions (at 20% of labour) and reclaims them via PAYE rather than Self Assessment. The process is more complex than for sole traders — you will need an accountant familiar with CIS for limited companies.
Is a limited company better for a plumber's liability?: In theory, yes — limited liability means your personal assets are separate from business debts. In practice, for plumbers, the main liability risk is covered by public liability insurance, which you need regardless of business structure. Many sole traders and limited companies carry the same £5m public liability policy. Limited liability is a genuine benefit if you take on large commercial contracts where financial exposure could be significant.
How much extra admin does a limited company involve for a plumber?: Significantly more than a sole trader. A limited company must file annual accounts with Companies House, file a Corporation Tax return, run PAYE payroll for your own salary, file confirmation statements, and maintain company registers. Most plumbers find they need an accountant at a cost of £1,000–£2,500 per year. As a sole trader, a basic accountant costs £300–£600 per year. The admin difference is real — factor it into any tax saving calculation.