VAT confuses more contractors than almost any other area of tax. Most know they need to register at some point. Far fewer understand when voluntary registration makes sense, how the Flat Rate Scheme actually works, or why a scheme that saves one contractor £2,200 per year leaves another slightly worse off than doing nothing.
This guide walks through the registration decision, the FRS vs standard rate calculation, and the specific test that catches most contractors out — the limited cost trader rule.
Do you need to register for VAT?
You must register for VAT when your taxable turnover exceeds £90,000 in any rolling 12-month period. This is the mandatory registration threshold for 2026/27. Two tests apply:
- The backward-looking test: If your rolling 12-month taxable turnover has exceeded £90,000, you must register within 30 days of the end of the month in which you crossed the threshold. Your registration then takes effect from the first day of the second month after you went over — so if you cross the threshold during July, you must notify HMRC by 30 August and your registration is effective from 1 September.
- The forward-looking test: If you have reasonable grounds to believe your turnover will exceed £90,000 in the next 30 days alone, you must register by the end of that 30-day period — and your registration is effective from the date you realised, not from the date turnover actually crosses the line. In practice, act as soon as you sign the contract that takes you over.
HMRC charges a "failure to notify" penalty for late VAT registration, calculated as a percentage of the VAT due from the date you should have registered. The percentage turns mainly on behaviour: broadly 30% where the failure was not deliberate, 70% where it was deliberate, and 100% where it was deliberate and concealed. Those are maximums, and disclosure reduces them substantially — for a non-deliberate failure disclosed unprompted within 12 months, the penalty can be reduced to nil. That is the single reason to act the moment you suspect you have crossed the threshold: the same mistake costs nothing if you raise it early and a great deal if HMRC finds it first. You will still owe the VAT itself, plus interest, either way.
Should you register voluntarily?
If your turnover is below £90,000, you have the option to register voluntarily. Whether this is worthwhile depends on your client base and your costs.
The voluntary registration decision
Are your clients VAT registered businesses? If yes, they can reclaim any VAT you charge them — it costs them nothing net. This removes the main commercial objection to voluntary registration.
Do you have meaningful VAT-able costs? Software subscriptions, equipment, phone, professional services. If you're spending £3,000+ per year net on business costs that carry 20% VAT, you're leaving £600 of reclaimable input VAT on the table each year by staying unregistered. Watch the net/gross distinction: £3,000 including VAT contains only £500 of reclaimable VAT (£3,000 ÷ 6), not £600.
Do you want to appear more established to larger clients? A VAT number on your invoice reads as a sign of an established business, and some procurement teams expect one. Be honest with yourself about the weight of this: since you are registering voluntarily, the number does not in fact evidence turnover above £90,000, so treat it as presentation rather than substance. It should not be the deciding factor on its own.
Are any of your clients non-VAT-registered consumers or small businesses? If so, adding 20% VAT to their invoices increases their cost with no reclaim option — this is the main downside of voluntary registration where your clients can't reclaim.
For most IT and engineering contractors serving business clients, voluntary registration is worth considering from the point your business costs reach meaningful levels — even well below the £90,000 threshold.
Standard rate VAT vs the Flat Rate Scheme
Once registered, you choose how to account for VAT. The two options that decide how much you pay are standard rate and the Flat Rate Scheme, and most of this guide is about choosing between them. Two further schemes affect only when you pay:
- Cash Accounting Scheme — you account for VAT when you are actually paid rather than when you invoice, which matters if your clients pay at 60 or 90 days. Available up to £1.35 million of taxable turnover. You cannot combine it with the Flat Rate Scheme, because FRS has its own cash-based turnover method that achieves much the same thing.
- Annual Accounting Scheme — one return a year with interim payments on account, available up to £1.35 million. This can be combined with FRS.
For a contractor on standard rate with slow-paying clients, cash accounting is usually the more valuable of the two and is worth asking about at registration.
Standard rate VAT
You charge 20% VAT on your invoices and collect it from clients. You reclaim 20% input VAT on all your business costs. The difference — output VAT collected minus input VAT reclaimed — is what you pay to HMRC each quarter. If your costs are high, standard rate can result in a relatively low net VAT payment.
The Flat Rate Scheme (FRS)
You still charge 20% VAT on invoices. But instead of calculating input and output VAT precisely, you pay a fixed percentage of your gross (VAT-inclusive) turnover directly to HMRC. The FRS percentage is set by sector — "Computer and IT consultancy or data processing" is 14.5%, "Management consultancy" is 14%, "Accountancy or book-keeping" is 14.5%, and "Architect, civil and structural engineer or surveyor" is 14.5%. You keep the difference between the 20% you charged and the flat rate percentage you pay.
Choosing the sector is your responsibility and it is not always obvious. An engineering consultant who is not an architect, civil or structural engineer or surveyor may instead fall under "Business services not listed elsewhere" at 12%. If your work spans two sectors you must pick the one generating the larger share of turnover and apply that single rate to everything — you cannot split your turnover between rates. HMRC will not revisit your choice later provided it was reasonable, so write down why you chose the sector you did and keep it with your VAT records.
The appeal of FRS is simplicity and a potential surplus — particularly for service contractors with low costs who retain more than they hand over.
Who can join, and when you have to leave
You can join the Flat Rate Scheme if your expected VAT-taxable turnover for the next 12 months is £150,000 or less, excluding VAT. For a contractor billing around £1,000 a day these limits arrive sooner than you might think, so it is worth checking each year rather than assuming FRS still applies.
Leaving works in two ways. You check your turnover on the anniversary of joining, and must leave if your total income including VAT for the year then ending exceeded £230,000 — though if you can satisfy HMRC in writing that income for the next 12 months will not exceed £191,500, and that the spike came from genuine one-off business activity that is not expected to recur, you may be allowed to stay. Separately, if at any point you have reasonable grounds to believe your income for the next 30 days alone will exceed £230,000, you must leave from the start of that 30-day period, and no concession applies.
Two further things to know before you join or leave. You cannot join if you have used and left the scheme in the previous 12 months, if your business is associated with another, if you are in or eligible to join a VAT group, or if you have been convicted of a VAT offence or accepted a compound penalty offer in the last 12 months. And once you leave, you cannot rejoin for 12 months — so treat a switch to standard rate as a decision for at least a year, not something to reverse next quarter.
In your first year of VAT registration you get a 1 percentage point reduction on your flat rate — so the 14.5% IT consultancy rate becomes 13.5%. The discount runs from the date you register for VAT, not from the date you join the scheme, and it applies until the day before the first anniversary of registration. If you join FRS six months after registering, you get six months of discount, not twelve.
One catch: you are not entitled to the reduction if you registered for VAT more than 12 months after you were required to do so. Claiming it beyond the first year of registration is one of the errors HMRC specifically lists as common on flat rate returns.
What actually counts as flat rate turnover
The percentage is only half the calculation. What you apply it to matters just as much, and this is where contractors overpay without realising.
Included: the VAT-inclusive value of all your standard, reduced and zero-rated supplies, plus any exempt income. Because zero-rated and exempt income go into the base, you pay the flat rate on income you charged no VAT on — so if those make up a larger share of your turnover than is typical for your sector, FRS can cost you money.
Excluded — and this one is worth real money to some contractors: supplies that are outside the scope of UK VAT drop out of flat rate turnover entirely. Services supplied to a business customer established outside the UK are generally outside the scope under the place of supply rules, so that income is left out of the calculation altogether while you still keep the scheme's simplicity on your UK work. A contractor with a substantial overseas client base can find FRS materially better than the arithmetic in this guide suggests. Non-business income and bank interest are also excluded.
Two related mechanics. Where you buy services from outside the UK and the reverse charge applies, those are handled outside FRS — excluded from flat rate turnover but recorded in boxes 1 and 4 of your return as they would be under normal accounting. And you cannot use FRS at all for supplies subject to a UK domestic reverse charge, which includes building and construction services under CIS — a real constraint for engineering and construction contractors rather than a technicality.
A common misunderstanding: the scheme simplifies how you calculate what you owe, not what you put on an invoice. You must still issue proper VAT invoices to VAT-registered customers showing VAT at the normal rate for the supply — 20% for most contracting work — never at your flat rate percentage. The flat rate is applied afterwards, to the VAT-inclusive total of everything you supplied in the period.
The FRS calculation: a worked example
An IT contractor with £100,000 annual turnover (excluding VAT) on FRS at 14.5%:
| Item | Amount |
|---|---|
| VAT charged to clients (20%) | £20,000 |
| Gross turnover including VAT | £120,000 |
| FRS payment to HMRC (14.5% × £120,000) | £17,400 |
| Surplus vs the VAT charged | £2,600 |
Read that £2,600 carefully: it is the gap between the VAT you charged and the VAT you handed over, not your saving. Under FRS you give up input VAT recovery, so the real comparison is against what you would have paid on standard rate — which is lower than £20,000. On the cost profile used later in this guide the true advantage is £2,200, not £2,600.
Even at £2,200 this looks attractive for no extra work. But there is a catch.
The limited cost trader rule
HMRC introduced the limited cost trader test in 2017 specifically to prevent low-cost service providers from benefiting too generously from FRS. Under this rule, if your business spends less than 2% of its gross (VAT-inclusive) turnover on goods — or less than £1,000 per year on goods — you are a limited cost trader and must use an FRS rate of 16.5%, regardless of your sector. The test is applied for each VAT return period, so the £1,000 figure is effectively £250 per quarter.
It's easy to underestimate the limited cost trader rate because 16.5% sounds close to the 20% standard VAT rate. But the 16.5% FRS rate is applied to your gross, VAT-inclusive turnover — not your net sales figure. Since gross turnover is 120% of net turnover (i.e. net sales plus 20% VAT), the 16.5% rate translates to an effective rate of 16.5% × 1.20 = 19.8% of your net sales. In other words, if you invoice £100,000 net (£120,000 including VAT), you hand over £19,800 to HMRC — almost as much as the £20,000 of VAT you actually charged. That leaves a £200 gap against the VAT you charged — and once you account for the input VAT you have given up by being on the scheme at all, a limited cost trader on 16.5% ends up roughly £200 worse off than standard rate, not better off. The worked comparison below sets this out.
The critical words here are relevant goods. These must be moveable physical items — stationery and other office supplies, cleaning products, stock, raw materials — and they must be used exclusively for the purposes of your business. That exclusivity test bites for home-based contractors: electricity supplying a house that contains your office is not exclusively for business and does not count.
The following do NOT count as relevant goods:
- Software subscriptions and anything downloaded or supplied electronically (Adobe Creative Cloud, Microsoft 365) — these are services. Standard off-the-shelf software supplied on a physical disk does count as goods, which is now rare enough to be a curiosity rather than a strategy.
- Professional subscriptions (ICAEW, LinkedIn premium) — services
- Travel and accommodation — services
- Postage and stamps — these are payments for services, not goods, despite arriving as physical items
- Food or drink for you or your staff — excluded even though physical
- Capital expenditure goods of any value, including laptops, phones and other electronic devices
- Rent, accountancy fees, advertising, and anything leased or hired — services, because ownership never transfers to you
- Anything bought purely to pass the test — see below
The obvious response to this rule is to spend £1,000 on stationery and escape the higher rate. HMRC closed that off explicitly: goods bought solely to meet the test are not relevant goods, because they are not being used exclusively for the purposes of the business. The example HMRC gives is a quantity of office materials that the business cannot reasonably use, and which is simply stockpiled or thrown away — even where the business would normally buy those same items in smaller amounts. Buying goods you genuinely need is fine. Buying goods to move a percentage is not, and the spend is wasted twice over.
For most service contractors, genuine relevant goods spend is minimal — a few pounds of stationery a year, if that. This means most contractors are limited cost traders by default, even if they spend thousands on business costs.
Capital items like laptops and equipment don't count toward the 2% goods test above, so they don't help you escape limited cost trader status. But there's a separate rule: on a single purchase of capital expenditure goods costing £2,000 or more including VAT, you can reclaim the input VAT in the normal way — even while using the Flat Rate Scheme. It's dealt with outside the FRS calculation rather than counted as "goods."
Three conditions matter. It must be one purchase, so £2,400 of kit bought from three suppliers across three months is three purchases and none of them qualifies — though a computer package (machine, monitor, printer, peripherals) bought together from one supplier counts as a single purchase. It must be goods, not services, so a leased laptop never qualifies because ownership never transfers. And when you eventually sell an asset you reclaimed VAT on, you must account for output VAT on the sale at the standard rate, not at your flat rate — which is easy to forget years later and is the point at which HMRC tends to notice.
| Contractor | Annual Goods Spend | 2% of Gross Turnover (£100k+VAT) | Limited Cost Trader? | FRS Rate |
|---|---|---|---|---|
| IT consultant, mostly software tools | £0 (software = services) | £2,400 | Yes — below 2% and £1,000 | 16.5% |
| UX designer, buys drawing tablets | £0 (tablets are electronic devices — capital, excluded) | £2,400 | Yes — no qualifying goods at all | 16.5% |
| Engineering consultant, buys PPE and materials | £3,500 | £2,400 | No — above both the 2% and £1,000 tests | 14.5%* |
*14.5% assumes the engineering consultant falls within "Architect, civil and structural engineer or surveyor". Other engineering consultancy may sit in "Business services not listed elsewhere" at 12% — check the sector list before relying on a rate. Note also that PPE and materials only count if used exclusively for the business and not bought to pass the test, and that construction services caught by the domestic reverse charge cannot go through FRS at all.
FRS at 16.5% — is it still worth it?
For a limited cost trader on 16.5% FRS, the surplus compared to standard rate narrows dramatically:
| Scenario | FRS at 14.5% | FRS at 16.5% | Standard Rate |
|---|---|---|---|
| VAT charged (£100k net turnover) | £20,000 | £20,000 | £20,000 |
| Paid to HMRC before input VAT | £17,400 | £19,800 | £20,000 |
| Input VAT reclaimed (on £2,000 net of VAT-able costs) | £0 (not reclaimable on FRS) | £0 (not reclaimable on FRS) | −£400 |
| Net VAT to HMRC | £17,400 | £19,800 | £19,600 |
| Annual position vs standard rate | +£2,200 better | −£200 worse | Baseline |
Both FRS columns are measured against the same standard-rate baseline of £19,600, which is why the 14.5% figure is £2,200 rather than the £2,600 gross surplus shown in the earlier example. The £400 difference is the input VAT you forgo by being on the scheme, and it scales with your costs: a contractor with £6,000 of VAT-able costs forgoes £1,200, cutting the 14.5% advantage to £1,400.
At 16.5% of gross turnover — equivalent to 19.8% of net sales — FRS is slightly worse than standard rate for most limited cost traders. The £200 is negligible in cash terms, but it points the wrong way, and standard rate also gives you input VAT recovery on future purchases that FRS does not.
If you are a limited cost trader (which most service contractors are), standard rate VAT is the better default. You reclaim input VAT on costs, maintain flexibility for future purchases, and avoid the administrative complexity of managing an FRS rate that changes with your cost profile. FRS at 14.5% is only meaningfully beneficial if your goods spend confirms you are not a limited cost trader.
Common VAT mistakes contractors make
- Missing the registration deadline — the rolling 12-month test catches contractors off-guard. Monitor your cumulative turnover against £90,000 monthly.
- Staying on FRS when they've become a limited cost trader — your cost profile can change year to year. Review your FRS status annually.
- Treating reimbursed expenses as outside VAT scope — if you invoice a client for expenses and add a mark-up, VAT may be due. Genuine disbursements (paid on behalf of the client, at cost, no mark-up) are treated differently.
- Misreading the de-registration test — it is forward-looking. You can apply to de-register when you expect taxable turnover for the next 12 months to be below £88,000, not simply because the last 12 months came in under it. Note also that you may have to account for VAT on stock and assets still held at de-registration, and that if you are on FRS you leave the scheme the day before your de-registration date.
- Applying the flat rate to net rather than gross turnover — HMRC lists this among the most common errors on flat rate returns. The percentage goes on the VAT-inclusive figure.
- Place of supply errors for overseas clients — if you provide services to a business customer outside the UK, the place of supply is generally outside the UK scope, which affects both your registration threshold calculation and, on FRS, your flat rate turnover. The reverse charge mechanism can apply on purchases. Take advice on this if you have non-UK business clients.
Practical setup: MTD for VAT
All VAT-registered businesses must keep digital records and file VAT returns through MTD-compatible software under Making Tax Digital. FreeAgent was on HMRC's list of compatible software as at August 2026 and submits quarterly returns directly to HMRC; check HMRC's current list before relying on any particular package. If you're registered for VAT and your bookkeeping is up to date, quarterly submission is largely automated.
VAT returns are typically due one month and seven days after the end of each quarter. A quarterly filing cycle is standard; monthly filing is available (and sometimes beneficial) for businesses that regularly receive VAT refunds.
Not sure which VAT scheme is right for you?
Every new client gets a VAT scheme analysis at onboarding — comparing FRS against standard rate on your specific turnover, cost profile and client mix.
Book a call →