Should I hire a VAT-registered builder?

VAT registration is not a quality signal. There are excellent non-VAT-registered builders and incompetent VAT-registered ones. But it does change the maths, and it tells you something about the scale of the business, which matters when you are about to commit £30,000 or more.

This guide covers when VAT registration adds 20% to your bill, when it doesn't, and the trade-offs that come with hiring at either end.

What VAT registration means in UK construction#

A business must register for VAT once its taxable turnover exceeds the VAT threshold, currently £90,000 over any rolling 12-month period (as of 2026). Many small builders operate just below this threshold deliberately. Once registered:

• The builder must charge VAT at 20% on most domestic refurbishment work, on top of the labour-and-materials price
• The builder can reclaim the VAT on materials and services they buy
• They must file VAT returns (typically quarterly) and remit the collected VAT to HMRC

A non-VAT-registered builder cannot charge VAT and cannot reclaim VAT they have paid on materials. The materials cost is simply absorbed into their cost base.

What this means for your quote#

For a £20,000 kitchen renovation:

That looks like a £4,000 saving for the non-VAT builder. In practice it is less, because the VAT-registered builder reclaims VAT on the materials they bought (which the non-VAT builder cannot), and so their £20,000 cost base contains effectively cheaper materials.

Whether the actual saving is £1,500 or £3,500 depends on the labour-to-materials ratio. Trade-heavy work (electrical, plumbing) is mostly labour and the saving is closer to the headline 20%. Materials-heavy work (a kitchen with £8,000 of cabinetry, an extension with significant timber and groundworks) is a smaller saving, often nearer 8–12%.

When work is zero-rated or reduced-rate#

Not all building work is at standard 20% VAT. The categories that matter for homeowners:

Zero-rated (0%):

• New-build residential dwellings
• Conversions of certain non-residential buildings into residential use (barns, offices, agricultural buildings)
• Approved alterations to listed dwellings, though this category was largely abolished in 2012 and now applies only to a narrow set of pre-existing contracts

Reduced-rate (5%):

• Conversions that change the number of dwellings (one house to two flats, or vice versa)
• Renovations of homes that have been empty for at least 2 years
• Certain energy-saving installations (insulation, heat pumps, solar panels) when supplied with installation, though the qualifying rules change periodically and you should ask the builder for the current HMRC reference

Standard-rate (20%):

• Almost all other domestic refurbishment work: kitchens, bathrooms, extensions on occupied homes, rewires, re-roofs

For zero- or reduced-rate work, the VAT advantage of a non-VAT-registered builder largely disappears: the VAT-registered builder charges 0% or 5% and still reclaims their input VAT on materials, making their effective cost base cheaper than the non-VAT-registered competitor's.

What VAT registration tells you about the business#

A VAT-registered builder is, by definition, doing more than £90,000 of taxable turnover per year. That implies:

• A team or multiple sub-contractors (rather than a single trade)
• Regular cashflow of a size that supports buying materials in advance
• A relationship with suppliers that allows discounts
• An accountant, because VAT returns are not optional and require proper bookkeeping

A non-VAT-registered builder is, by definition, below the threshold. That can mean:

• A skilled sole trader or two-person crew genuinely choosing a small-scale lifestyle
• Or a business that suppresses turnover deliberately to stay under the threshold, which limits their team size and their ability to take on larger jobs

Neither status is good or bad on its own. The relevant question is whether the builder is matched to the size of your job.

When to insist on VAT-registered#

For specific scenarios, hiring a VAT-registered builder is worth the extra cost:

• Projects over £40,000. The headline VAT cost is real, but the scale of the project benefits from a builder with structural capacity to manage trades, materials, and cashflow.
• Listed buildings or planning-permitted work. Administrative complexity favours a builder with proper bookkeeping.
• Insurance-backed warranty schemes. The major schemes (FMB warranty, TrustMark) are easier for VAT-registered businesses to qualify for because of the audit trail.
• Reduced-rate work (empty home renovations, energy retrofits). The VAT structure works in your favour, and the builder must be VAT-registered to apply the reduced rate.

For projects under £15,000, a competent non-VAT-registered builder is usually the better-value choice.

The cash-discount trap#

A "cash discount" of 10–20% offered for paying in cash, off the books, is almost always tax evasion. The savings come from the builder not declaring the income. Three reasons not to take it, even when offered unprompted:

1. You are participating. HMRC can (and occasionally does) investigate the customer side of suspected evasion. The legal exposure is higher than most homeowners realise.
2. You have no contractual position. A cash job, off the books, is harder to enforce in any small-claims court because you cannot produce the paperwork the court expects.
3. Your insurance is weakened. Public liability and household insurance both require legitimate contracted work to respond correctly to claims arising from it.

If you want to genuinely save money, hire a non-VAT-registered builder who will give you a proper invoice for the lower (legitimate) price, not a VAT-registered builder offering to do the work off the books.

What to ask before signing#

• "Are you VAT-registered? Can I see the registration number?"
• "Is the price quoted inclusive or exclusive of VAT?"
• "Will the work fall under standard, reduced, or zero rate?"
• "Will the invoice show the VAT separately?"
• "If reduced rate, what is the HMRC reference for the qualifying work?"

A genuine VAT-registered builder answers these readily; the answers are part of the paperwork they file routinely. A non-registered builder should be able to confirm they are not VAT-registered and explain why their prices already reflect that.