Declaration of Trust UK 2026 — Splitting Beneficial Interests in Rental Property and the Form 17 HMRC Election

Married couples and civil partners — the Form 17 election

HMRC applies a special rule to married couples and civil partners that requires additional steps beyond a bare declaration of trust:

• The s.17 ICTA 1988 default — equal shares: Under s.836 Income Tax Act 2007 (formerly s.17 ICTA 1988), where a married couple or civil partners jointly own an asset producing income, HMRC automatically treats the income as arising equally (50/50) — regardless of the actual beneficial ownership split. This is the 'living together' presumption. Even where the couple hold the property 90/10 in beneficial terms, HMRC will assess them 50/50 unless a Form 17 election is in place
• Form 17 — the declaration of actual beneficial interest: A Form 17 is an election filed with HMRC jointly by both spouses or civil partners declaring that the actual beneficial interest in the property differs from the 50/50 presumption and specifying the actual split. Form 17 is filed online or by post to HMRC's Self Assessment centre. The election must be accompanied by evidence of the actual beneficial interest — most commonly a declaration of trust executed as a deed
• The declaration of trust must pre-date or accompany the Form 17: The deed of trust recording the unequal beneficial interest must exist before or simultaneously with the filing of Form 17. HMRC will reject a Form 17 where there is no contemporaneous deed of trust evidencing the declared split. The deed must be a formal legal document (not merely a letter or memorandum) and should be executed under deed (signed, witnessed, and delivered)
• Timing and effect: A Form 17 election takes effect from the date it is filed with HMRC (not from the date the deed of trust is executed). HMRC will recognise the new split from the date of receipt of Form 17. A Form 17 continues to apply until it is revoked, the beneficial interest changes, or the couple cease to be married/civil partners and living together. If the beneficial interest is changed again (for example, further redistribution), a new Form 17 and deed of trust are required
• Example — income tax saving: Partner A is a higher-rate (40%) taxpayer with employment income. Partner B has no other income and uses their personal allowance and basic-rate band. A rental property produces £24,000 per annum net of allowable expenses. At 50/50, each partner is assessed on £12,000 — Partner A pays 40% on their share (£4,800 in tax), Partner B pays 20% or 0% (depending on their personal allowance usage). By restructuring to 80% Partner B / 20% Partner A via a deed of trust and Form 17: Partner A is assessed on £4,800 (20% or 40% depending on rate band), Partner B is assessed on £19,200 (personal allowance and basic rate covers most of this). Net tax saving can be significant

Unmarried co-owners — declaration of trust without Form 17

Where rental property is owned jointly by persons who are not married or in a civil partnership, the Form 17 procedure is not required:

• No s.836 presumption for unmarried co-owners: The 50/50 income presumption in s.836 ITA 2007 applies only to spouses and civil partners who are living together. For all other joint owners (unmarried cohabitants, siblings, business partners, friends), HMRC taxes rental income in proportion to the beneficial interest actually held — as evidenced by the property's title documents and any deed of trust
• Declaration of trust — the key document: A declaration of trust (or deed of trust) executed between unmarried co-owners records the actual beneficial interest split agreed between the parties. Any split is possible — 99/1, 60/40, 30/70. The deed should be executed as a formal deed (signed by all parties, witnessed, and delivered) and should specify precisely: the proportions in which each party holds the beneficial interest; how any future proceeds on disposal are to be divided; how any capital improvements are to be treated; and any changes in beneficial interest that may occur in the future (for example, if one party makes a larger capital contribution)
• HMRC and the declaration of trust: HMRC will accept a declaration of trust as evidence of the actual beneficial interest split for income tax purposes. Each party should report their actual share of rental income on their self-assessment tax return. Where the split differs significantly from the legal title (particularly where one party has 1% and the other 99%), HMRC may question the arrangement and request to see the deed. The deed should be commercially rational — a tax-motivated arrangement with no substance behind it is at risk of challenge under the Ramsay principle
• Practical uses: A declaration of trust is used by unmarried co-owners to: record agreed investment ratios where contributions to the purchase price differ; allocate income to the lower-rate taxpayer; protect each party's separate interest in the equity on a relationship breakdown; and establish a basis for division of proceeds on sale. Solicitor advice is recommended for all declarations of trust — particularly where significant sums are involved

CGT implications — transfers of beneficial interest

Changing the beneficial interest in a property has capital gains tax implications:

• Transfers between spouses/civil partners — no gain, no loss: Under TCGA 1992 s.58, transfers of assets between spouses or civil partners who are living together are treated as no gain, no loss disposals — the transferee acquires the asset at the transferor's original acquisition cost (plus indexation allowance where applicable). This means a married couple can restructure the beneficial interest between themselves without triggering an immediate CGT liability. The receiving spouse's acquisition cost is the original cost — not the market value at the date of transfer
• Transfers between unmarried co-owners — market value rule: Transfers of a beneficial interest between parties who are not spouses or civil partners are disposals at market value under TCGA 1992 s.17 if made to connected persons (siblings, parents, children, business partners). The transferor is treated as having received the market value of the interest transferred — triggering a CGT liability based on the difference between that market value and the original acquisition cost. For rental property, annual CGT exemption (£3,000 for 2024/25 and subsequent years) can be applied but may not fully cover the gain
• Principal private residence relief: Where the property is or has been the transferor's main residence, private residence relief (s.222 TCGA 1992) and letting relief may reduce or eliminate the CGT liability on the transferred interest. For a rental property that has never been the transferor's main home, no PPR relief is available
• CGT on future disposal: Where beneficial interest is restructured to 90/10, the 90% beneficiary will be assessed on 90% of any future capital gain on disposal. The lower-rate CGT taxpayer may pay 18% (basic rate residential property) vs 24% (higher rate residential property) on their share, creating a further tax advantage on eventual sale
• HMRC scrutiny and Ramsay: HMRC has become increasingly vigilant about artificial beneficial interest structures designed purely to avoid tax. A beneficial interest split must reflect commercial reality — where a spouse holds 1% but actively manages the property, or where the split bears no relation to actual capital contributions, HMRC may challenge the arrangement under anti-avoidance principles (Ramsay [1982] AC 300 and subsequent case law). Always take professional tax advice before implementing a declaration of trust for tax purposes

SDLT — when does a declaration of trust trigger stamp duty?

Executing a declaration of trust can sometimes trigger Stamp Duty Land Tax (SDLT):

• Bare declarations — no SDLT in most cases: Where a declaration of trust is executed between co-owners to record an existing beneficial interest arrangement (one that reflects how the property was always intended to be held), there is generally no SDLT event — no chargeable consideration is given. The declaration is documenting the position rather than effecting a transfer
• Transfer of beneficial interest subject to mortgage — SDLT on debt assumption: Where the beneficial interest is restructured between co-owners and one party assumes responsibility for a greater share of the mortgage debt, the assumption of mortgage debt constitutes chargeable consideration for SDLT purposes. Under FA 2003 s.43(6), where a purchaser assumes a debt as part of the consideration, the debt assumed is treated as chargeable consideration. If the restructured party is already a property owner, the 3% SDLT surcharge will apply to the entire chargeable consideration
• Example: A property is owned 50/50 by two sisters with a £200,000 mortgage. They restructure to 90/10 — the 90% sister assumes an additional 40% of the mortgage debt (£80,000). The £80,000 debt assumption is chargeable consideration. SDLT applies at the residential rates (including the 3% surcharge if either sister already owns another residential property). At 3% + 5% (total 8% on the excess above threshold): SDLT on £80,000 would be calculated accordingly
• Professional advice essential: The SDLT implications of beneficial interest restructuring are complex and depend on the specific circumstances — including the mortgage position, the parties' ownership of other properties, and the structure of the transaction. Always take specialist SDLT advice before executing a declaration of trust where mortgaged property is involved

Frequently asked questions