Connected Parties Transactions: Market Value SDLT Rules
Buying property from or selling to a family member, business partner, or controlled company triggers mandatory SDLT on market value — not the contract price. The connected person rules under s1122 CTA2010 and s49 FA2003 apply broadly and cannot be sidestepped by underpricing.
Last verified: March 2026
Key Takeaways
- •The s1122 CTA2010 definition of "connected person" covers spouses, civil partners, siblings, parents, children, and companies under common control.
- •Section 49 FA2003 requires SDLT to be calculated on market value (not contract price) where buyer and seller are connected — even if the agreed price is lower.
- •Gifting property at £1 does not avoid SDLT — the full market value is the chargeable consideration.
- •Sub-sale relief and certain other reliefs are denied where parties are connected.
- •Corporate transactions between companies under common control are subject to the same market value rule unless group relief or another specific exemption applies.
In this article
Who Is a Connected Person? (s1122 CTA2010)
For SDLT purposes, the definition of "connected person" is imported from s1122 of the Corporation Tax Act 2010, applied via s1122 and s1123 CTA2010. An individual is connected to: their spouse or civil partner; the relatives of themselves or their spouse (siblings, ancestors, and lineal descendants — i.e., parents, grandparents, children, grandchildren); the spouses of those relatives; and a company that the individual controls or which is controlled by people connected to them.
A company is connected with another company if both are controlled by the same person or group of connected persons. Control for this purpose means holding more than 50% of the voting rights, issued share capital, or distributable income. Where two friends each own 50% of their respective companies and decide to trade properties between those companies, those companies are not connected in the absence of a closer relationship. But siblings who each own 50% of their respective companies would likely be connected.
Importantly, "relatives" in the SDLT context does not extend to uncles, aunts, or cousins. Step-parents and step-children are not connected persons under s1122 CTA2010, though they may be connected under the broader FA2003 definition in some contexts. The precise scope should be checked with a specialist before any inter-family property transaction.
Note on cohabitants: An unmarried partner who is not a civil partner is not a connected person under the strict s1122 definition. However, HMRC may consider whether the arrangement constitutes a scheme or arrangement under anti-avoidance provisions if the structuring appears designed to avoid the connected person rules.
Market Value Rule Under s49 FA2003
Section 49 of the Finance Act 2003 provides that where a land transaction involves connected persons, the chargeable consideration is the greater of the actual consideration given and the market value of the subject matter of the transaction at the effective date. Market value follows the TCGA 1992 definition: the price the property would fetch if sold in the open market between a willing buyer and a willing seller, with no artificial assumptions about urgency or special interest buyers.
The rule is mandatory — there is no discretion to ignore it or apply a discount for family or commercial reasons. A solicitor advising on a connected party transaction must report the correct chargeable consideration (market value) in the SDLT land transaction return, even if that figure is higher than the purchase price. Filing a return on the basis of the agreed price knowing that the parties are connected and the market value is higher constitutes an incorrect return.
HMRC has powers under s83 FA2003 to raise a discovery assessment if it discovers that a return was filed on an understated chargeable consideration. The time limit for discovery assessments is generally four years from the filing date, extended to six years if the error is careless, and 20 years for deliberate errors. Interest runs from the date the tax was originally due.
Family Purchase Worked Example
A son purchases his mother's house at £200,000 as an act of family assistance. The property has a market value of £450,000 at the date of completion. The son does not currently own any other residential property (no additional surcharge applies).
| Basis for SDLT | Amount | SDLT Due |
|---|---|---|
| Contract price (what son pays) | £200,000 | £1,500 |
| Market value (chargeable consideration under s49) | £450,000 | £12,500 |
Despite only paying £200,000, the son owes SDLT of £12,500 — an additional £11,000 compared with the tax that would have been due on the agreed price alone. The difference arises because s49 FA2003 mandates use of market value. The son must fund the additional SDLT from his own resources even though he paid below market value for the property itself.
Gift scenario: If the mother had gifted the property at £1, the entire £450,000 market value would still be the chargeable consideration. There is no minimum price below which the market value rule ceases to apply — £1 transactions and outright gifts are fully caught by s49.
Reliefs Denied for Connected Parties
Several SDLT reliefs that might otherwise be available are expressly denied where the parties are connected. Sub-sale relief under s45 FA2003, which can relieve SDLT on the first leg of an A-B-C transaction chain, is specifically excluded where A and B (or B and C) are connected. This prevents families from using sub-sale structures to pass property up or down a family chain without full SDLT on each link.
Group relief under Schedule 7 FA2003 is available for intra-group transfers, but this is a carefully defined relief (requiring 75% ownership) and does not apply simply because two companies have the same controlling individual. The relief must be positively claimed and requires conditions to be met both at completion and for three years afterwards. It does not eliminate the market value calculation — rather, it allows deferral on the basis that the transfer is at arm's length within the group.
First-time buyer relief is unaffected by the connected persons rule — a son genuinely purchasing his first property (even from a connected party) can claim FTB relief provided all other conditions are met. However, the relief is calculated on the market value chargeable consideration under s49, not on the actual (discounted) price agreed.
Corporate Context: Common Control Companies
The connected person rules apply with full force to corporate property transactions. Where a sole trader incorporates a property business and transfers properties to the new company, the individual and the company are connected (because the individual controls the company). SDLT is therefore due on the market value of each property transferred, not on any nominal consideration.
Similarly, where an individual owns two companies and directs one to sell property to the other, both companies are connected to the individual (and therefore to each other). The s49 market value rule applies. There is no inter-company arm's length exemption based purely on the fact that both companies are separate legal entities; the test is about control and connection, not legal formality.
Partnership-to-company transfers are particularly complex, as the partnership SDLT rules in Schedule 15 FA2003 interact with the connected persons provisions. The SLP (sum of lower proportions) test in Schedule 15 determines the chargeable consideration for such transfers, and the connection between partners and the company receiving the property is highly relevant to the SLP calculation.
Common Pitfalls and HMRC Approach
The most frequent error in connected party transactions is simply failing to recognise the connection. A buyer's solicitor who is told the property is being bought at below market value from a family member — but who files the SDLT return on the agreed price without checking s49 — is exposed to a professional negligence claim if HMRC raises a discovery assessment. Solicitors and conveyancers must positively check whether the parties are connected and, if so, obtain a market valuation.
Undervaluation is another common issue. Even where a solicitor obtains a valuation, if that valuation proves to be below what HMRC considers the open market value, a shortfall in SDLT arises. HMRC's Valuation Office Agency (VOA) will challenge valuations it considers too low, and the burden of proving market value is on the taxpayer. A robust, independent RICS valuation obtained at or around the effective date is the best protection.
Finally, the connected party rules apply to non-monetary consideration as well. If a property is transferred in exchange for the assumption of a mortgage or in settlement of a debt between connected parties, the market value rule still applies. The total chargeable consideration is the higher of the value of the property exchanged and the market value, not the face value of any debt or liability assumed.
Frequently Asked Questions
Who counts as a connected person for stamp duty?
For SDLT, "connected person" is defined by reference to s1122 CTA2010. It includes spouses, civil partners, siblings, parents, grandparents, children, grandchildren, their spouses, and companies controlled by the same person or group. It does not extend to cohabitants, uncles, aunts, or cousins unless there is a separate connection through control of a common company.
Can I sell property to family below market value to save stamp duty?
No. Section 49 FA2003 mandates that SDLT is calculated on the higher of the actual consideration and market value where the parties are connected. Selling at below market value — including gifting at £1 — does not reduce the SDLT liability. The buyer must pay SDLT on full market value regardless of the price agreed.
How does the market value rule work for connected party transactions?
The SDLT land transaction return must be filed using the market value of the property as the chargeable consideration, not the agreed purchase price if that is lower. Market value follows the TCGA 1992 definition — what the property would fetch in the open market. A professional RICS valuation at the effective date is advisable to support the figure declared in the return.
Are gifts of property subject to stamp duty?
Yes, where the gift is between connected persons. A gift at £1 or £0 (nil consideration) from a connected party is treated as a transaction for market value consideration under s49 FA2003. SDLT is due on the full market value. Between unconnected parties, a genuine gift with no consideration (and no debt assumed by the recipient) results in no chargeable consideration and no SDLT — but HMRC will scrutinise whether any consideration is truly nil.

Emma Richardson, MRICS
Chartered Surveyor & Property Tax Specialist
Emma Richardson is a RICS-qualified Chartered Surveyor with over 12 years of experience in UK property taxation. She founded Stamp Duty Calculator to help buyers understand the complex world of property transaction taxes.
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