Anti-Avoidance Rules on Share Exchanges and Reorganisations (UK Property Companies)

If you have a BTL portfolio in a limited company and you want to add a parent holdco for IHT planning, transfer your shares to a new family investment company in exchange for new shares, or merge your portfolio with a partner's into a single group, you are doing a share exchange. The question that decides whether you pay capital gains tax now or roll the gain into the new shares is whether HMRC accepts that the main purpose of the arrangements is not tax avoidance.

This page is the practitioner-aimed primer on share-exchange and reconstruction anti-avoidance as it applies to property-business owners and their accountants. We walk the share-exchange relief at TCGA 1992 s.135 (read with s.127), the parallel reconstruction relief at s.136 and the asset-level reconstruction route at s.139, the main-purpose anti-avoidance gate at s.137 as substantially restructured by Finance Act 2026 with effect from 18 March 2026, the s.138 advance-clearance procedure, and the income-tax-side and corporation-tax-side counterparts at ITA 2007 Part 13 Chapter 1 and CTA 2010 Part 15. The page closes on a seven-step practitioner sequence.

The Property-SPV Use Cases for Share Exchange

Three property-owner cases dominate the share-exchange workload:

• Inserting a parent holdco above an existing operating SPV. The shareholder of the existing BTL company gives their original shares to a newly-formed parent holding company, receiving parent shares in exchange. The parent then sits above the BTL company and the assets remain in the BTL company. The use case is normally governance, succession planning, future share-class architecture for adult children, and IHT planning at the holdco level.
• Merging two SPVs into a group by share exchange. Two BTL portfolios consolidate into a single group. Shareholders of B swap into A in exchange for new A shares. The use case is operational scale, financing efficiency, debt restructuring on a group basis, and (sometimes) preparation for a partial or full exit.
• Family-internal share reorganisation. The most common case is moving SPV shares into a family investment company so that the FIC's share-class architecture can be used to allocate growth and income across the family in a tax-efficient way going forward. The mechanic is the same share exchange, with the FIC playing the role of the receiving company. Our complete guide to family investment companies walks the share-class side; the s.137 anti-avoidance gate that sits over the transfer is the subject of this page.

Each of the three is mechanically a TCGA 1992 s.135 share exchange where the statutory conditions are met. The statutory cases for s.135 to apply are: the receiving company holds more than 25 percent of the original company's ordinary share capital after the exchange; the exchange results from a general offer to original-company members which would give the receiving company control; or the receiving company holds the greater part of the voting power in the original company.

What Relief Does TCGA s.135 Actually Provide?

Read with TCGA 1992 s.127 ('Equation of original shares and new holding'), s.135 treats the share exchange as not a disposal for CGT purposes. The shareholder does not crystallise the gain at the exchange. The gain rolls into the new shares, which step into the original acquisition date and base cost.

Without s.135, the exchange would be a deemed disposal at market value under TCGA 1992 s.17 (and s.18 connected-party rules where the parties are connected, which they almost always are in family-internal property-SPV reorganisations). A BTL company holding £4.2 million of property with a base cost of £2.6 million would trigger an immediate CGT charge on a £1.6 million gain at the corporate CGT rate. s.135 defers that charge until the shareholder eventually disposes of the new (parent or merged-group) shares for cash or other consideration.

The parallel relief at s.136 applies on a 'scheme of reconstruction', which the case-law (notably Mytravel Group Plc v HMRC) defines by reference to substantial-identity-of-shareholders and continuity-of-business tests. Demergers, group reorganisations and split-by-business reconstructions are typical s.136 territory. The asset-level rollover at s.139 handles inter-company business transfers in a scheme of reconstruction, working alongside s.136 at the shareholder level.

The Section 137 Anti-Avoidance Gate (and the FA 2026 Substitution)

TCGA 1992 s.137 disapplies the s.135 and s.136 reliefs where the main purpose, or one of the main purposes, of the arrangements is to reduce or avoid liability to capital gains tax or corporation tax. The test is a main-purpose test, not a sole-purpose test. Commercial reasons may dominate but coexist with tax avoidance as a co-equal main purpose, and s.137 still bites.

The Finance Act 2026 substituted s.137(1) with new subsections (1) to (1C) with effect from 18 March 2026, and added a wide new 'arrangements' definition at s.137(7). The s.137(7) definition catches 'any agreement, understanding, scheme, transaction or series of transactions (whether or not legally enforceable)'. The substitution also omitted former subsections (2) and (3) and modified the assessment-procedure subsection at s.137(4).

The substantive width of the new definition is significant. Informal arrangements between connected parties (a parent and adult child agreeing on a sequence of post-exchange share-buybacks, two co-investors handshake-agreeing a cash-extraction in the year after a merger) are now expressly within the anti-avoidance reach. Pre-FA-2026 firm briefings on share-exchange clearance practice may not capture the new framework; the post-March-2026 vintage of any practitioner reference is now load-bearing.

The s.138 Advance-Clearance Route

TCGA 1992 s.138 allows either party to a proposed exchange or reconstruction to apply to HMRC ('the Board') in advance for confirmation that s.137 will not apply. The clearance route is the practitioner discipline for almost every property-SPV reorganisation; deals proceeding without clearance are unusual outside contexts where the s.137 risk is plainly absent (which is rare for family-internal share-class restructures).

The mechanic:

1. Application under s.138(1): the applicant sets out the proposed transaction, the commercial reasons, the absence of tax-avoidance as a main purpose, and any tax planning that forms part of the broader picture. Disclosure is full; minimising the tax-planning element reads to HMRC as suppression of the truth.
2. Further particulars under s.138(2): HMRC may request further particulars within 30 days of the application. The applicant has 30 days to respond.
3. Decision under s.138(3): HMRC notifies its decision within 30 days of the application or of the further-particulars compliance.
4. Tribunal escalation: failure by HMRC to notify within the relevant 30-day window triggers a tribunal-escalation route within a further 30 days under the s.138 mechanism.

A positive clearance is operational gold: the deal proceeds with statutory certainty that s.137 will not apply on the disclosed facts. A negative clearance does not mean s.137 will apply; it means HMRC will not pre-commit. Proceeding without clearance carries discovery-assessment exposure under TMA 1970 s.29 (4-year standard window, 6-year carelessness, 20-year deliberate concealment) for the long tail.

What HMRC Looks For in a Clearance Application

A commercial-purpose narrative documented from contemporary records. The discipline is to evidence the commercial picture from the period before the deal was structured, not to construct it after the deal is on paper.

• Succession planning. Family decision to bring adult children into the ownership structure. Documented in board minutes, family-meeting notes, share-allocation drafts.
• Governance structure. Move from sole-shareholder operational SPV to a parent-and-subsidiary structure for cleaner board separation. Documented in articles of association and shareholders' agreement drafts.
• IHT planning. Pre-positioning for an eventual generation transfer. The fact that IHT planning exists in the picture is not itself a problem for the s.137 test; what matters is whether IHT planning is THE main purpose (typically it is part of a broader picture rather than the sole driver).
• BTL portfolio aggregation. Operational scale, financing efficiency on a group basis, debt restructuring. Documented in financial-projection workings and lender correspondence.
• Debt restructuring. Refinance of property-level debt to holdco-level facility. Documented in lender term sheets and refinancing proposals.

Where tax planning IS part of the picture, HMRC accepts the picture as long as tax avoidance is not the main purpose. The application should not minimise the tax-planning element; it should frame tax planning as part of a broader commercial-and-family agenda. Board minutes prepared specifically for the clearance application (rather than dated contemporaneously) are the single most common evidential weakness.

What Happens If Clearance Is Refused or Never Sought

The share exchange is fully effective at company-law level regardless of tax treatment. The shares are issued, the registers updated, the new structure is in place. The CGT consequence is the live risk: HMRC may seek to apply s.137, treat the exchange as a disposal at market value under s.17 connected-party rules, and assess CGT at the corporate CGT rate (where the disposal is by a company-shareholder) or at the individual residential or non-residential CGT rate (where the disposal is by an individual shareholder of an SPV).

The counteraction can occur years later under the TMA 1970 s.29 discovery-assessment window: 4 years standard, 6 years for carelessness, 20 years for deliberate concealment (per §27.1 lock on discovery time-limits). The discipline is: where clearance is refused, restructure the deal (different parties, different timing, different commercial framing) and reapply, rather than proceed into the unclear position. A refused clearance is not the end of the transaction; it is the start of a different transaction design.

The ITA 2007 Part 13 Chapter 1 Income-Tax Trap

For individual shareholders, a separate anti-avoidance regime sits over the picture. ITA 2007 Part 13 Chapter 1 catches transactions in securities that produce an income-tax advantage. The operative architecture:

• s.684: the person liable to counteraction is the person 'in a position to obtain... an income tax advantage in consequence of a transaction in securities or two or more such transactions'.
• s.685: the close-company route. Receiving consideration 'in connection with the distribution by or assets of a close company' can be recharacterised as a dividend, even where the transaction took the form of a share exchange or sale.
• s.687: definition of 'income tax advantage'.
• s.701: parallel clearance application route, paralleling TCGA s.138 on the income-tax side.

Where the property-SPV reorganisation involves shareholder cash extraction alongside the share-for-share leg (a cash element to consideration, a parallel share buyback, a redemption of a class of shares), the income-tax route is often the bigger risk than s.137 CGT. The Cleary v IRC line of cases established that consideration paid out of company reserves in a structured exchange can be recharacterised as a dividend. IRC v Joiner established the commercial-purpose test for s.701 clearance. The discipline is to model the income-tax side in parallel with the CGT side and to apply for both clearances together.

The Corporation-Tax-Side Counterpart: CTA 2010 Part 15

Where the property-SPV reorganisation is structured at the company level (share-for-share between two trading entities, group reorganisation under FA 1988 Schedule 18-style continuity rules), the corporation-tax-side anti-avoidance regime applies in parallel with TCGA s.137. CTA 2010 Part 15 (Transactions in securities) catches transactions that produce a corporation-tax advantage; the clearance route is at CTA 2010 s.748.

The discipline that follows from the three parallel regimes (TCGA s.137 for CGT, ITA 2007 Part 13 for individual income tax, CTA 2010 Part 15 for corporation tax) is three-route clearance: an application under s.138, an application under s.701, and an application under s.748, often submitted concurrently. The applications can be linked in cover narrative but are formally separate, each with its own 30-day HMRC response window and each addressed to the relevant statutory anti-avoidance counterpart.

When TCGA s.139 Applies Instead

TCGA 1992 s.139 is the asset-level rollover for inter-company business transfers on a scheme of reconstruction. Distinct from s.135 and s.136, which work at the shareholder level. s.139 works at the asset level: where one company transfers a property-business to another company as part of a reconstruction, s.139 gives the transferor no-gain-no-loss treatment on the underlying assets.

The practical use: where a BTL portfolio (the assets) is moved between two companies as part of a wider reconstruction, s.139 handles the asset-side rollover while s.136 handles the shareholder-side rollover. The two reliefs typically operate in the same transaction. The clearance route for s.139 sits at s.139(5), separate from s.138 but operating on similar main-purpose principles.

The Seven-Step Practitioner Sequence

For any property-SPV reorganisation that runs through a share exchange or reconstruction, the operational sequence:

1. Draft the commercial reasons memo before structuring the deal. Family, portfolio, governance, financing-restructure or IHT-planning objective. Contemporaneous record of the commercial picture. The memo is the foundation document for any later clearance application.
2. Frame the share-exchange or reconstruction structure around the commercial picture. Tax planning may be part of the picture, but should not be the main picture. The s.137 main-purpose test bites where tax avoidance is 'the main purpose, or one of the main purposes'.
3. Apply for advance clearance under TCGA 1992 s.138. Full disclosure of the commercial reasons, the deal mechanics, and any tax planning that forms part of the broader picture. The application should NOT minimise tax planning; minimisation reads as suppression.
4. Apply for parallel clearance under ITA 2007 s.701 and CTA 2010 s.748. Three separate but linked applications. The three regimes operate in parallel and each has its own clearance route. Submit concurrently where practicable.
5. Wait for HMRC response. Typically 30 days per application. Applications often run concurrently. If HMRC requests further particulars under any of the three regimes, respond within 30 days.
6. Proceed only on positive clearance. A refused clearance is not the end of the transaction; it is the start of a different transaction design. Restructure (different parties, different timing, different commercial framing) and reapply rather than proceeding into the unclear position.
7. Document the deal contemporaneously. Board minutes, board resolutions, valuations, deed of variation, completion certificates. The post-exchange operational record matters: cash extractions, share buybacks or redemptions in the 12 to 24 months after the exchange can reopen the s.137 question if they form part of a pre-formed plan caught by the new s.137(7) 'arrangements' definition.

Adjacent Pages and Further Reading

The share-class architecture that this anti-avoidance framework sits over is covered in the family investment company cluster, starting with our family investment company: property worth it? orientation page. The s.162 incorporation relief for owners moving an unincorporated property business into a company is covered at our complete guide on incorporating a company in UK; that is asset-level relief and operates on a different test from the share-level s.135 framework discussed here. The separate transactions-in-UK-land anti-avoidance regime under CTA 2010 Part 8ZB and ITA 2007 Part 9A operates on transactions whose purpose is to disguise profits from disposals of UK land as gains; that is a different test from the s.137 main-purpose test but conceptually adjacent.