What the flat rate scheme actually does
The VAT flat rate scheme (FRS) replaces the standard method of calculating VAT (output tax collected less input tax on purchases) with a single fixed percentage applied to your VAT-inclusive income. HMRC publishes sector rates ranging from around 4% to 14.5% depending on your trade. The difference between the 20% VAT you charge your clients and the lower flat rate you pay HMRC is yours to keep, and your bookkeeping is simplified because you do not track input VAT on most purchases.
In its original design, the FRS rewarded lower-overhead businesses by allowing them to retain a share of the VAT they collected. A contractor billing purely labour at a sector rate of 14.5% on the old rules would keep around 5.5 percentage points of VAT-inclusive turnover as a tax-free gain. On a contractor billing £100,000 net per year (£120,000 VAT-inclusive), that equalled roughly £6,600 a year in retained VAT.
That calculation no longer works for most contractors, and understanding why is the core of this decision.
The limited-cost trader rule: what changed in 2017 and why it still dominates
From 1 April 2017, HMRC introduced the limited-cost trader category. If your spending on goods (not services) in a VAT period is either less than 2% of your VAT-inclusive turnover or less than £1,000, you are a limited-cost trader and must use a flat rate of 16.5%, whatever your sector.
At 16.5% on VAT-inclusive turnover, the arithmetic changes entirely. On a £120,000 VAT-inclusive billing figure, you pay HMRC £19,800 at the flat rate but collected £20,000 of VAT from clients. The spread is £200 for the year, less than the bookkeeping time it saves. For most contractors there is nothing meaningful to gain from the FRS once the 16.5% rate applies.
The mechanics of the limited-cost test and exactly how HMRC defines goods versus services for this purpose are covered in detail on our limited-cost trader guide. The short version: most labour-only contractors (IT, management consulting, engineering, finance, legal) spend far less than 2% of turnover on physical goods, and so the 16.5% rate applies to them automatically. Software licences, cloud subscriptions, and professional indemnity insurance are all services, not goods, for the purpose of this test.
Which contractors are most and least likely to benefit
Before running numbers, it helps to understand which profiles typically clear the limited-cost threshold and which almost never do.
Labour-only contractors (IT, software, management consulting, finance, legal, marketing). Their core cost base is their own time. Business expenditure runs to accountancy fees, professional indemnity insurance, software subscriptions, and sometimes a home office element. All of these are services, not goods, for the limited-cost test. Annual goods spend is typically nil to a few hundred pounds on stationery and minor consumables, far below 2% of turnover. The 16.5% rate applies in every period. The FRS offers these contractors nothing.
Contractors who regularly buy and supply goods alongside their services. A construction contractor buying materials, an audio-visual contractor purchasing hardware, or an engineering contractor procuring specialist components may genuinely clear the limited-cost threshold each quarter. If goods spending is above 2% of VAT-inclusive turnover consistently, the relevant sector rate applies and the FRS can produce a real saving. This profile is relatively uncommon among the IR35 audience but does exist, particularly in trades-adjacent and technical sectors.
Contractors in a transitional phase. A contractor who has recently bought capital equipment (a server, professional camera kit, specialist testing hardware) may clear the threshold in the period of purchase but fail it in every surrounding period. The period-by-period test means the FRS may benefit them in one quarter but not in others. Over a full year the result could be neutral or slightly negative once modelling is done.
Understanding your own profile honestly is the starting point. If you are in category one, the rest of the FRS arithmetic is largely irrelevant.
The VAT registration decision comes first
Before asking whether the FRS is right, you need to decide whether to register for VAT at all. The two questions are separate.
Compulsory registration
Registration is compulsory once your VAT-taxable turnover exceeds £90,000 in any rolling 12-month period (or where you expect to cross that figure in the next 30 days). Both the registration and deregistration thresholds (the deregistration threshold is £88,000) have been frozen since 1 April 2024. A contractor billing at a typical day rate will often cross £90,000 within their first year of full-time contracting, at which point registration is not a choice.
Voluntary registration
Voluntary registration below £90,000 is worth considering for most contractors. The commercial case is straightforward: the majority of end clients are VAT-registered businesses that can recover any VAT you charge, so your effective rate is not higher for them. Meanwhile, being registered lets you reclaim input VAT on accountancy fees, software, equipment and other business costs. It also brings you within the Making Tax Digital for VAT digital-records requirements, but those are not administratively onerous for a contractor using accounting software.
The decision to register voluntarily is separate from the question of which accounting method to use. Registering does not commit you to the FRS. Many contractors register voluntarily and use standard VAT accounting, which is often the better choice for the reasons set out in this guide.
For a full walkthrough of the registration process, timing, and how to choose between methods at registration, see our contractor VAT registration guide.
FRS entry conditions and eligibility
To join the FRS your expected taxable turnover for the next 12 months must not exceed £150,000 excluding VAT. This is assessed at the point you apply. You apply to HMRC (form VAT600FRS or online through your VAT account) and HMRC confirms your sector and flat rate.
A one-percentage-point discount applies in your first year of VAT registration, reducing your sector flat rate by 1% for twelve months from the date you registered for VAT. For a contractor at 16.5% this brings the rate to 15.5% in year one. On a £114,000 VAT-inclusive billing figure the difference is around £1,140, which is small but real. Even with the first-year discount the 15.5% rate still barely improves on standard accounting for a labour-only contractor, but it is worth factoring in if you are right at the margin in your first year.
You may join the FRS at the point of initial registration or at any time afterwards.
When to leave the flat rate scheme
Two situations require you to leave, and several more make it sensible to go voluntarily.
Mandatory exit
You must leave the FRS if your total business income (VAT-inclusive) in any 12-month period exceeds £230,000, or if you expect it to exceed that in the next 30 days. This is a higher bar than the entry threshold (which is measured ex-VAT) and in practice affects a smaller number of contractors, but it is worth monitoring as rates rise.
Voluntary exit
You may leave voluntarily at the beginning of any VAT period. Reasons to consider leaving include:
- Your goods spend has dropped (or was never high enough) and you are consistently a limited-cost trader paying 16.5%, where standard accounting is equally advantageous.
- You have made a significant capital purchase (equipment, computing hardware, specialist tools) and want to reclaim the input VAT, which is blocked under the FRS except in narrow circumstances.
- Your billing includes material costs that have increased, and the standard-rate calculation now produces a better result.
- Your accountant has modelled both methods against your actual figures and standard wins.
Leaving is straightforward: write to HMRC requesting deregistration from the scheme from the start of your next VAT period and revert to standard accounting from that date.
Modelling the FRS against standard VAT: a worked example
Consider a software development contractor in 2026/27 billing £95,000 net per year (£114,000 VAT-inclusive), with annual business expenditure on services (accountancy, professional indemnity, software subscriptions) of £4,000 plus VAT (£800 input VAT). There is no significant goods spend.
Standard VAT accounting: output VAT £19,000 minus input VAT £800 equals net payment to HMRC £18,200.
FRS at 16.5% (limited-cost rate): 16.5% multiplied by £114,000 equals net payment to HMRC £18,810.
Under these fairly typical figures, the FRS costs this contractor an extra £610 a year. The standard method is better. Swap the flat rate to 14.5% (the pre-2017 "computer and IT consultancy" sector rate) and the FRS would cost £16,530, saving around £1,670, but only if the contractor can stay out of the limited-cost category. The test is whether goods spend clears 2% of £114,000 (£2,280) or £1,000. With no meaningful goods spend, it will not.
The numbers shift if the contractor regularly buys physical equipment. At £2,500 of annual goods spend the limited-cost test is satisfied (2% of £114,000 is £2,280, and £2,500 exceeds it), the 14.5% sector rate could apply, and the FRS produces a saving. That is the exception, not the rule, for most desk-based contractors.
Second scenario: a contractor who clears the limited-cost test. Take a specialist AV engineer billing £90,000 net per year (£108,000 VAT-inclusive) who spends £3,000 on goods per year (well above 2% of £108,000, which is £2,160). Suppose their sector flat rate is 12%. Under the FRS they pay HMRC 12% of £108,000, which is £12,960, against £18,000 of output VAT collected, keeping £5,040. Under standard accounting they pay £18,000 output VAT minus input VAT on goods (£3,000 at 20% equals £600) and on services (£1,500 at 20% equals £300), totalling £900 in recoverable input VAT: net payment to HMRC £17,100. The FRS saves this contractor £4,140 per year. That is a meaningful gain, and it illustrates why the FRS can still be the right choice for contractors whose expense profile genuinely supports it. The key is that goods spend, sector rate, and billing volume all have to align in the contractor's favour simultaneously.
The decision framework: four questions
Work through these in order before deciding whether to join or stay on the FRS.
1. Do you have genuine, recurring goods spend above the limited-cost threshold?
Calculate your expected goods spend for a typical VAT period and compare it to 2% of your expected VAT-inclusive turnover and to £1,000. "Goods" means physical goods your business uses or consumes, not services (even if delivered digitally). If your spend on goods is consistently below both thresholds, the 16.5% rate will apply in every period and the FRS is unlikely to benefit you. Go directly to standard accounting.
2. What is your published sector flat rate?
HMRC publishes a table of sector flat rates in VAT Notice 733. If you clear the limited-cost test, the relevant rate depends on the nature of your services. A sector rate of 14.5% generates a 5.5 percentage-point spread on VAT-inclusive billing; at 12% the spread is 8 percentage points. The higher the spread and the higher your billing, the more compelling the FRS becomes if you can stay out of the limited-cost category.
3. Are your input VAT costs significant?
Under the FRS you give up the right to reclaim input VAT on most purchases (there is a narrow capital-goods scheme exception for single items over £2,000 including VAT). If you have meaningful input VAT on equipment, specialist software, or sub-contracted services, standard accounting lets you reclaim it and the FRS locks it out. Model the full picture, not just the flat-rate spread.
4. Does the administrative simplicity have real value for you?
For some sole-traders or very small operations the FRS saves meaningful bookkeeping time. For a contractor using accounting software (which all contractors should be doing for MTD for VAT compliance anyway), the standard method is not significantly more complex. Do not pay to stay on the FRS purely for simplicity if the numbers do not support it.
Voluntary registration and the FRS: getting the sequence right
A common scenario: a contractor is billing below £90,000 and considering both voluntary registration and whether to use the FRS. The right order is:
- Decide whether voluntary registration is worthwhile on its own merits (client mix, input-VAT recovery, commercial positioning).
- If you decide to register, run the limited-cost test against your expected figures to determine whether you will face the 16.5% rate.
- Model standard versus FRS using your actual billing and expense figures.
- Apply for the FRS only if the model supports it, not as a default alongside registration.
Joining the FRS at registration without modelling it first is a common and avoidable mistake. Many contractors assume the FRS is automatically the clever choice and find out later that the limited-cost rate has been costing them money each quarter.
How the FRS interacts with the broader tax position
VAT is separate from income tax and corporation tax, but the accounting method affects the numbers that flow into your tax returns in a few ways worth noting.
Under the FRS, the VAT retained (the spread between what you charged and what you paid HMRC) is taxable income for corporation tax purposes. Under standard accounting you simply pass the net VAT through, so there is no retained spread to include. For most contractors the FRS spread (if any) is small, but your accountant needs to account for it correctly.
The FRS also does not affect the core limited-company tax position: salary, dividends, corporation tax on profits, and the efficiency of employer pension contributions are unaffected by which VAT method you use.
Where the FRS interaction matters most is for contractors also thinking about expenses. Under standard accounting you reclaim input VAT on accountancy fees, subscriptions, and other deductible expenses, which reduces the gross cost. Under FRS you cannot, so the gross cost of those expenses is effectively higher. This reinforces the standard-accounting case for contractors whose deductible expenses carry meaningful VAT.
Practical steps: reviewing your current position
If you are already on the FRS, it is worth reviewing annually. Pull your last four VAT returns and for each period calculate:
- VAT charged to clients (output tax).
- FRS payment made (flat rate multiplied by VAT-inclusive income).
- Input VAT you could have reclaimed under standard accounting.
If your actual FRS flat rate is 16.5% and the output-minus-input figure under standard accounting would have been lower, you are paying a premium to stay on the FRS. The calculation takes less than twenty minutes with your VAT returns and purchase invoices in front of you.
Switching from FRS to standard accounting requires notifying HMRC in writing from the start of your next VAT period. Your accountant can handle this as part of a routine review. There is no penalty for leaving the scheme, and once you are back on standard accounting you can track input VAT on all business purchases from that point forward.
A note on Making Tax Digital for VAT
All VAT-registered businesses are now within Making Tax Digital for VAT and must keep digital VAT records and submit returns using compatible software. This applies whether you are on the FRS or standard accounting. MTD for VAT does not change the FRS decision, but it does mean the "simpler bookkeeping" argument for the FRS is narrower than it once was: if your accounting software is already handling MTD submissions automatically, the incremental complexity of tracking input VAT under standard accounting is low.
MTD for Income Tax is a separate obligation that affects sole traders and landlords, not PSC directors: a limited-company contractor whose income is salary and dividends from the company is generally outside MTD for Income Tax.
Getting the decision right
The flat rate scheme was designed to reduce administrative burden and reward lower-overhead businesses. For labour-only contractors it largely ceased to be advantageous from April 2017. The question of whether it suits your specific situation turns on three real variables: your goods spend in each VAT period, your sector flat rate, and the input VAT you would recover under standard accounting. Run the model with your actual figures before deciding, and review it every year as your billing mix and expense profile change.
For a detailed walkthrough of the limited-cost trader test and exactly how HMRC applies it period by period, see our limited-cost trader and FRS mechanics guide. The mechanics guide covers the goods-versus-services distinction, the split-business rules, and the specific calculations HMRC expects.
If you want a specialist contractor accountant to model both VAT methods against your real figures and review your broader tax position, our team works with limited-company contractors across all sectors. See our contractor accountancy services or visit our IR35 review page if your engagement status is also in question.