Editor’s note: this is general educational information about a UK tax mechanism, not investment advice. It is drawn from the official legislation and HM Revenue and Customs guidance listed at the end.
Analysis: the exemption follows the venue, not the company
The structure rewards a reading that most cost comparisons miss. Nothing in section 99(4B) tests the buyer, the trade size, the sector or the risk of the issuer. The test is where the securities are admitted and whether they are listed anywhere. A company whose shares are admitted to AIM and nowhere else produces an exempt purchase; the same company, listed on an official list, produces a chargeable one. That is why the exemption survives a move of the trade offshore. HMRC is explicit that eligible securities qualify wherever they are traded, which follows directly from section 86’s indifference to where the agreement is made and who the parties are. Venue of admission is the variable; venue of execution is not.
The recognition conditions in section 99A also show what the exemption is aimed at. Neither test asks whether a market is liquid or well regulated. One is a size test on the population of issuers, the other a growth test written into admission requirements. A market that grows into large issuers can therefore drift out of the first condition over time, since the calculation is backward looking across the qualifying period and, as HMRC notes, cannot be satisfied by a brand new market until the second calendar year in which it has admitted companies. The 2024 increase of the threshold from £170 million to £450 million moved that boundary substantially without changing the underlying design.
What the documents do not establish is any effect of the exemption on the cost of capital or on trading volumes, and none of the cited sources measures one. A reader tracking this mechanism would watch three things instead: the recognised growth market list at STSM041330, which is amended by HMRC rather than by statute; the threshold in section 99A(5)(a), which the Treasury may alter by regulations under section 99A(13); and the accuracy of the exemption flag in CREST for any particular line of stock, since the refund route exists precisely because that flag can lag the legal position.
What the documents say
Most of the cost of owning UK shares is visible. Commission appears on the contract note, the spread is on the screen, and platform fees arrive monthly. One charge behaves differently. Stamp Duty Reserve Tax is calculated, deducted and paid over without the buyer filing anything, because the tax was designed around the settlement system rather than around a tax return. It also stops at a boundary that has nothing to do with the size of the trade or the sophistication of the buyer, and everything to do with which market the shares are admitted to.
What the 0.5% charge attaches to
The charge sits in Part IV of the Finance Act 1986. Section 87 applies where one person agrees with another to transfer chargeable securities for consideration in money or money’s worth, and subsection (6) sets the rate at 0.5 per cent of the amount or value of that consideration, computed by reference to each £100 or part of £100. The trigger is the agreement, not the delivery of the shares. Section 87(3) fixes the relevant day as the day the agreement is made, or, where the agreement is conditional, the day the condition is satisfied.
Geographic reach is deliberately wide. The Act states that the charge applies whether or not the agreement is made or effected in the United Kingdom, and whether or not any party is resident or situate in any part of the United Kingdom. What matters is the security, not the person. HMRC’s public guidance puts the same point in plainer terms: tax is due when a buyer acquires existing shares in a company incorporated in the UK, an option to buy shares, an interest in shares, rights arising from shares, or shares in a foreign company that keeps a share register in the UK.
The same guidance marks out where the charge does not reach. Nothing is due on shares received for nothing, on a subscription to a new issue, on the purchase of units in a unit trust from the fund manager, or on the purchase of shares in an open-ended investment company from the fund manager. HMRC’s manual explains why new issues fall outside the net: the shares vest and are registered in the purchaser’s name without a stock transfer form, and because they are issued rather than transferred there is no agreement to transfer chargeable securities for SDRT purposes. Paper transfers are a separate regime. Stamp duty proper is a charge on instruments and, per the published guidance, applies to a stock transfer form only where the transaction is over £1,000. There is also a higher 1.5% rate, applied where relevant securities of a UK-incorporated company are transferred into a depositary receipt arrangement or a clearance service, under sections 67, 70, 93 and 96 of the same Act.
Why nobody files a return
The collection point is the settlement system. HMRC describes CREST as the system that settles transactions and collects SDRT, and the tax status of each security is held there at what the manual calls a static data level. The exemption or liability is a property of the security record itself, applied when the trade is input, rather than a calculation the buyer performs afterwards. The effect is that the tax is discharged inside the same process that moves stock against cash.
That design has consequences when the flag is wrong. HMRC contemplates a buyer being charged the tax on securities that had already become eligible for exemption, in the window between eligibility and the settlement system being updated, and directs that buyer to claim a refund. The reverse error is handled by the CREST member: cancel and re-instruct the transaction with the correct stamp payable flag, pay on a non-settling own account transfer, or account for the tax outside CREST by paying HMRC directly. Euroclear UK and International Ltd, which operates CREST, maintains the list of securities eligible for exemption, and companies are told to submit whatever self-certificate or notification the relevant market or Euroclear requires so that their securities are flagged correctly.
Stamping of paper instruments moved in the same direction, though later and less completely. The manual records that stamping was traditionally carried out by impressing embossed stamps on the instrument, and that an electronic method of stamping was introduced in March 2020.
How a market becomes exempt
The exemption for growth market shares works by definition rather than by relief. Section 99(4B) of the Finance Act 1986 excludes from the meaning of chargeable securities those admitted to trading on a recognised growth market but not listed on that or any other market. HMRC’s guidance draws out the distinction that makes the drafting work: shares are not listed on recognised growth markets, they are admitted to trading, with listed taking its meaning from section 1005 of the Income Tax Act 2007. Because the securities are not chargeable securities at all, both the 0.5% and the 1.5% charges fall away. The exemption was introduced on 28 April 2014.
Recognition is an application process with statutory tests. Section 99A provides that a market is recognised as a growth market only if the Commissioners are satisfied, on evidence provided by the market, that it qualifies, and that it must be a recognised stock exchange or a qualifying UK multilateral trading facility meeting one or both of two conditions. The first is that a majority of the companies admitted to trading on it have market capitalisations below a threshold, measured as the average of closing market capitalisations on the last trading day of each calendar month across the qualifying period. HMRC states that the figure has been £450 million since 1 January 2024, and was £170 million before that. The second condition is an admission requirement obliging companies to demonstrate compounded annual growth in gross revenue or employment of at least 20% over the three periods of account preceding admission.
The published list is short. Four markets have been recognised since 28 April 2014: the Alternative Investment Market, Euronext Growth Dublin, which took that name from the Enterprise Securities Market on 4 February 2019, the High Growth Segment, and the AQSE Growth Market of Aquis Stock Exchange, previously the NEX Exchange Growth Market and originally the ISDX Growth Market. Four Nasdaq First North markets, in Copenhagen, Helsinki, Reykjavik and Stockholm, were added with effect from 8 August 2017.
