VAT is one of those things most trades ignore until it stops being ignorable — usually when turnover creeps up and someone mentions a threshold, or a commercial client asks for your VAT number and you haven’t got one.

The concepts are simpler than the paperwork suggests. Here’s the plain-English version: what VAT is, when registration stops being optional, and what changes on your quotes.

General information, not tax advice. Thresholds, rates and rules change — check gov.uk for current figures and talk to an accountant about your own situation.

What VAT actually is

VAT is a tax on what your customer buys, not a tax on you. Once registered you add it to your prices, collect it on HMRC’s behalf and hand it over — and in return you reclaim the VAT you’ve paid on business purchases: materials, tools, van costs, fuel.

Every VAT return is essentially one subtraction:

VAT you charged customers (output tax)
minus VAT you paid suppliers (input tax)
= what you pay HMRC — or what they refund you, if you paid out more than you took in.

The money you collect was never yours. The classic VAT disaster is treating a healthy balance as profit, spending it, then finding the quarter’s bill is due.

When you have to register

Registration becomes compulsory once your VAT-taxable turnover passes a threshold set by HMRC. Two things trip people up more than the number itself:

It’s a rolling 12 months, not your accounting year. You check the last twelve months at the end of every month, not just at year end. One big job can push you over sooner than expected.
There’s a forward-looking test too. If you expect to pass the threshold within the next 30 days alone — you’ve just landed a large contract, say — you register straight away, without waiting for the money to arrive.

Turnover means your sales, not your profit, and it includes materials you supply as well as labour — so a trade billing a lot of materials through the books gets there faster than one on labour-only work at the same take-home.

Don’t take a threshold figure from a forum post, an old article, or from me — it’s reviewed periodically. Get the current amount, deadlines and late-registration penalties from gov.uk’s VAT registration guidance. Registering late is the expensive mistake: HMRC will generally want the VAT you should have charged whether you charged it or not.

Should you register voluntarily?

You can register before you have to. Whether that’s clever or daft depends almost entirely on who your customers are — on whether they can reclaim the VAT you add.

	Mostly domestic customers	Mostly commercial, trade or landlord clients
Effect of adding VAT	Prices effectively go up — householders can’t reclaim it	Little real effect — clients reclaim it
Competitiveness	You look dearer than unregistered rivals	You look like a serious outfit
Verdict	Usually wait until you have to	Often worth doing early

The rest of the case for going early: you reclaim VAT on a van, tools and stock, you stop watching the threshold every month, and you may be able to reclaim on some pre-registration purchases (time limits apply — check gov.uk). Against it: quarterly returns, digital records and one more deadline to miss.

The awkward spot is a domestic trade just under the threshold, where crossing it means either your margin takes the hit or your quotes get less competitive overnight. Some hold below deliberately, others push well past so the volume covers it. Drifting over without noticing is the only wrong answer.

What changes on your quotes

Once you’re registered, the way you present a price matters more than it used to.

Domestic customers think in gross. A householder hears one number and assumes it’s what leaves their account. Show the total including VAT prominently, with net and VAT broken out beneath.
Commercial customers think in net. They’ll reclaim the VAT, so net is their real cost. Quote net and show VAT as a separate line.
Always label it. “£X plus VAT” or “£X including VAT” — never a bare number. Ambiguity here is the easiest way to lose the difference in an argument at the end of a job.
Put your VAT number on every quote and invoice — commercial clients need it to reclaim.

If you itemise quotes line by line rather than sending a lump sum, this is mostly a presentation change — the VAT sits at the bottom next to the subtotal. Lump-sum quotes are where the “was that inc or exc?” arguments happen.

Note too that not everything in construction carries the standard rate: certain new-build and conversion work can be zero-rated or reduced-rated, and getting it wrong either way is costly. If you do that work, read HMRC’s guidance on buildings and construction.

Telling existing customers

If you register mid-year, your regulars will notice. Say it plainly and early: from a given date your invoices include VAT, here’s the number, and if they’re registered themselves it makes no practical difference. Quietly absorbing it destroys the margin you worked out in your day rate; hiding it until the invoice lands destroys trust.

The domestic reverse charge, in one section

This one catches out subcontractors. For most construction services supplied between VAT-registered businesses within the CIS, the supplier doesn’t charge VAT at all — the customer accounts for both sides of it on their own return. You invoice for the work, state on it that the reverse charge applies and that the customer must account for the VAT, and you collect nothing. What that means for you:

It doesn’t apply to end users — a householder, or a business having work done for itself rather than supplying it on. Normal rules apply there.
It covers services and the materials supplied as part of them.
Your cash flow changes. You’re no longer holding customers’ VAT between quarters, and you may start getting refunds rather than paying, if you’re buying materials with VAT and charging none on your labour.

Whether it applies to a given job depends on the parties, the work and the customer’s status — check HMRC’s reverse charge guidance and get your customer’s VAT and CIS status confirmed in writing before you invoice.

The Flat Rate Scheme, briefly

An option for smaller businesses: instead of tracking VAT on every sale and purchase, you pay HMRC a fixed percentage of your VAT-inclusive turnover and generally can’t reclaim VAT on purchases, apart from certain capital assets.

Less admin, occasionally slightly less tax — but there’s a catch aimed squarely at trades. Spend relatively little on goods and you can be classed as a “limited cost business”, landing on a higher rate that usually kills the benefit. And a trade buying serious quantities of materials often does better on standard accounting anyway, because that input tax is reclaimable. The eligibility limit and sector percentages both change: get the current position from gov.uk and have your accountant run both methods against your real figures.

Habits that keep VAT boring

Put the VAT aside in a separate account as it comes in. Every trade who’s been stung says the same.
Keep digital records. Registered businesses must keep records and file using compatible software under Making Tax Digital — check the current requirements on gov.uk.
Keep every purchase receipt. No valid VAT invoice, no reclaim — a photo the day you buy beats a shoebox in March.
Reconcile quotes to invoices — if the quote said “plus VAT”, so must the invoice. Same consistency handling materials and markup properly gives you.

The takeaway

VAT isn’t complicated in principle: collect it from customers, reclaim it on purchases, pay HMRC the difference. Registration becomes compulsory at a threshold measured over a rolling twelve months, and going voluntary is mostly a question of whether your customers can reclaim it.

So: get the concepts straight, take the current numbers from gov.uk rather than anyone’s memory, keep the money separate, and let an accountant check the decisions that actually cost money — voluntary registration, the Flat Rate Scheme, and whether the reverse charge applies to you.

Queezy lets you show VAT properly on a branded, itemised quote — net, VAT and total, so nobody argues about whether the price included it. Join the waiting list for early access.

VAT for Tradespeople: A Plain-English Guide