There is no single best tax structure for every UK landlord. The right answer turns on total income, portfolio size, leverage, intended hold period, and whether profits are drawn for living costs or retained for reinvestment. This guide compares the five mainstream structures (sole-trader, joint ownership with Form 17, general partnership, limited liability partnership, and limited company) under 2026/27 rules and shows the worked maths for the four scenarios that cover most UK landlords.
This is the applied decision guide. The mechanical depth of the limited-company route sits in our BTL limited company complete guide; the SDLT-on-incorporation mechanics live in our SDLT on incorporation guide.
What 2026/27 Actually Looks Like for Landlords
Three confirmed rules dominate the structure choice in 2026/27:
- Section 24 finance cost restriction. Individual landlords cannot deduct mortgage interest from rental income. Instead, a 20% basic-rate tax credit applies. A higher-rate landlord with £30,000 of mortgage interest loses £6,000 of relief every year compared to pre-2017 rules. Companies are unaffected.
- 5% SDLT additional-dwellings surcharge. In force since 31 October 2024, replacing the 3% that ran 2016-2024. Applies to any individual buying an additional dwelling and to any company buying a residential dwelling.
- MTD for ITSA cycle. Live from 6 April 2026 for sole-trader landlords with qualifying income above £50,000. Threshold drops to £30,000 from 6 April 2027 and £20,000 from 6 April 2028. Limited companies are outside MTD for ITSA.
One scheduled change also shapes the conversation:
- Separate property-income tax rates (22% basic, 42% higher, 47% additional). A 2% surcharge on property income above the normal income tax rates was announced in the Autumn Budget and is scheduled to apply from 6 April 2027. The provision sits in the draft Finance Act 2026, expected to receive Royal Assent before the start of 2027/28. Plan on the basis that the surcharge applies from 6 April 2027.
Structure One: Sole Trader (SA105)
The default for most UK landlords. Rental profits and losses are reported on the SA105 property pages of the Self Assessment return. Income is taxed at the individual's marginal income tax rate. CGT applies on disposal at 18% (basic) and 24% (higher) for residential property, with a £3,000 annual exempt amount in 2026/27.
When it wins
- Basic-rate taxpayer with rental profits well within the basic rate band.
- Low-leverage or mortgage-free portfolio (so Section 24 bite is minimal).
- Plan to dispose within 4-5 years (incorporation breakeven not reached).
- Single property or small portfolio under roughly £400,000 of gross value.
When it loses
- Higher-rate taxpayer with material mortgage interest.
- Retaining profits for reinvestment (cash extraction tax does not apply).
- Above the MTD for ITSA threshold (£50,000 from 6 April 2026, £30,000 from 6 April 2027) so compliance burden is real.
Structure Two: Joint Ownership with Form 17
For married couples and civil partners, joint ownership of property in unequal beneficial shares (typically held as tenants in common) and a Form 17 declaration to HMRC can route more of the rental profit to the lower-earning spouse.
How it works
The default for jointly-owned property between spouses is a 50/50 income split, regardless of the actual beneficial ownership (ITA 2007 s.836). To override that default, you need:
- A declaration of trust establishing the actual beneficial ownership in the unequal share (e.g. 99/1 in favour of the lower-earning spouse).
- Form 17 filed with HMRC within 60 days of being signed, declaring the unequal income split matching the unequal beneficial ownership.
HMRC will accept any genuine beneficial split (down to 100/0), provided the income split matches the beneficial split exactly. They will not accept an arbitrary 99/1 income split on a 50/50 beneficial ownership.
Worked example
Jamal earns £80,000 PAYE (higher-rate). Aisha works part-time and earns £15,000 PAYE (basic-rate). They jointly own three Birmingham buy-to-lets generating £18,000 of net rental profit.
| Treatment | Jamal's tax on rental profit | Aisha's tax on rental profit | Combined |
|---|---|---|---|
| Default 50/50 (£9,000 each) | £3,600 (40%) | £1,800 (20%) | £5,400 |
| Form 17 1/99 (£180 / £17,820) | £72 (40%) | £3,564 (20%) | £3,636 |
Annual saving from the Form 17 route is roughly £1,750 a year, without any other structural change. The Form 17 / declaration of trust route is the highest-return, lowest-cost piece of structure planning available to most UK landlord couples. It is also the most under-used.
Structure Three: General Partnership
Two or more individuals running the property letting as a genuine partnership, with a partnership agreement, partnership tax returns (SA800), partnership accounts, and joint operations. Profits are allocated to partners on the partnership-share basis and taxed in each partner's own hands. Section 24 still applies.
When it makes sense
Partnership is rarely the destination structure on its own. The most common reason to run a partnership is as a deliberate prelude to incorporation: a genuine letting partnership that has been trading as such for two years or more can transfer into a wholly-owned limited company under FA 2003 Sch 15 para 10 with nil SDLT (the partnership route). For a portfolio worth £750,000+, the SDLT saved by the partnership route is typically £45,000-£55,000, which dwarfs the cost of running the partnership for the two-year window.
What HMRC look for
HMRC's SDLT Manual at SDLTM34000 onwards requires evidence of substance: partnership agreement, SA800 filings, partnership bank account, joint borrowing where possible, operational evidence (tenancy agreements between the partnership and tenants, insurance in the partnership name, lender correspondence to the partnership). Husband-and-wife joint ownership without partnership infrastructure does not qualify.
Structure Four: Limited Liability Partnership (LLP)
An LLP combines pass-through taxation (each member is taxed on their share of profit as if a sole trader) with corporate-style limited liability. It is registered at Companies House and files annual accounts but is taxed as a partnership.
When LLP is right
- Multiple unrelated investors who want pass-through taxation and limited liability.
- Family investment structures with adult children involved in the management.
- Joint ventures with bespoke profit and capital share arrangements that a limited company's standard share structure does not accommodate.
What LLP does not solve
Section 24 applies to LLP members in the same way as to individual landlords. So LLP does not provide the mortgage-interest deduction that a limited company does. For most higher-rate landlords, that means LLP is not the answer to the Section 24 problem; the limited company is.
Structure Five: Limited Company
A limited company owning the property directly. Corporation tax at 19% on profits up to £50,000, 25% above £250,000, and marginal-relief rates in between. Mortgage interest is deducted in full. Profits can be retained inside the company or extracted as salary or dividends.
When it wins
- Higher-rate or additional-rate taxpayer with material mortgage interest.
- Plan to retain profits for reinvestment (so dividend tax on extraction is deferred or never incurred during accumulation phase).
- Portfolio above roughly £500,000 of gross value with a 7-year+ hold horizon.
- Intention to grow further (each new acquisition benefits from full mortgage deduction).
When it loses
- Basic-rate taxpayer (Section 24 is irrelevant to them; corporation tax + dividend tax is no better than personal income tax).
- Low-leverage or mortgage-free portfolio (no Section 24 bite to relieve).
- Plan to draw every pound of profit as dividends (extraction tax stacks on top of corporation tax).
- Short intended hold (the SDLT cost of getting in does not repay itself).
The Four Scenarios That Cover Most UK Landlords
Worked figures for 2026/27 across four representative landlord profiles. Each uses gross rents of £50,000, mortgage interest of £20,000, and other allowable costs of £6,000. Personal allowances are assumed used by other income. All figures rounded.
Scenario 1: Basic-rate sole trader (other income £35,000)
| Item | Sole trader | Limited company (retain all profit) | Limited company (extract all profit as dividends) |
|---|---|---|---|
| Taxable rental profit | £44,000 | £24,000 | £24,000 |
| Corporation tax | n/a | £4,560 (19%) | £4,560 |
| Personal income tax on profit | £8,800 (20%) | n/a | £2,580 (8.75% dividend) |
| Section 24 credit | (£4,000) | n/a | n/a |
| Net tax | £4,800 | £4,560 | £7,140 |
For a basic-rate landlord, sole trader is broadly equivalent to limited company on retained profits, and decisively better than limited company on extracted profits. Sole trader wins.
Scenario 2: Higher-rate sole trader (other income £75,000)
| Item | Sole trader | Limited company (retain) | Limited company (extract) |
|---|---|---|---|
| Taxable rental profit | £44,000 | £24,000 | £24,000 |
| Corporation tax | n/a | £4,560 | £4,560 |
| Personal income tax on profit | £17,600 (40%) | n/a | £6,548 (33.75% dividend) |
| Section 24 credit | (£4,000) | n/a | n/a |
| Net tax | £13,600 | £4,560 | £11,108 |
| Annual saving vs sole trader | baseline | £9,040 | £2,492 |
For a higher-rate landlord retaining profits, limited company saves £9,040 a year. Payback on a typical £45,000-£55,000 SDLT cost is around 5-6 years.
Scenario 3: Married couple, mixed earnings (one higher-rate, one basic-rate)
The right answer is rarely "incorporate the joint portfolio". The right first move is Form 17 to push rental profit to the basic-rate spouse, which often eliminates the need to incorporate at all.
| Treatment | Net annual tax on rental profit |
|---|---|
| Default 50/50 sole trader | £8,800 |
| Form 17 1/99 to basic-rate spouse | £5,200 |
| Limited company (retain all profit) | £4,560 |
| Limited company (extract all profit) | £11,108 |
Form 17 saves £3,600 a year at zero one-off SDLT cost. Limited company saves £4,240 a year but costs £45,000+ of SDLT to set up. Form 17 wins on payback grounds for any married couple where one spouse is in a materially lower band.
Scenario 4: Higher-rate, geared 3-property portfolio, retaining profits to grow
Gross rents £90,000, mortgage interest £40,000, other costs £12,000. Higher-rate marginal status, retaining all profit for the next acquisition.
| Item | Sole trader | Limited company |
|---|---|---|
| Taxable rental profit | £78,000 | £38,000 |
| Corporation tax / Income tax | £31,200 (40%) | £7,220 (19%) |
| Section 24 credit | (£8,000) | n/a |
| Net tax | £23,200 | £7,220 |
| Annual saving | baseline | £15,980 |
Payback on a typical £55,000 SDLT cost is around 3.5 years. This is the textbook case for incorporation.
The Decision Matrix in Practice
| Situation | Best structure | Key reason |
|---|---|---|
| Basic-rate, 1-2 properties, low leverage | Sole trader | Section 24 bite minimal; company adds cost without saving tax |
| Married couple, one higher-rate spouse, mixed earnings | Form 17 declaration of trust | Highest return per pound of complexity; zero SDLT cost |
| Higher-rate, geared portfolio, retaining for growth | Limited company | Section 24 eliminated, corporation tax beats 40%/45% personal rates |
| Higher-rate, geared portfolio, drawing all profits | Mixed (sole trader for cash income, company for retained growth) | Dividend tax on full extraction erodes the company advantage |
| Multiple unrelated investors, bespoke profit splits | LLP or limited company with multiple share classes | Either pass-through (LLP) or controlled distribution (company) |
| Family with adult children | Company with growth shares / freezer shares | Future appreciation flows into next generation; IHT planning |
| Single high-value London capital-growth play | Sole trader (or joint with Form 17) | CGT 18%/24% on sale beats corporation tax + dividend tax on extraction |
| Property developer (trading, not investment) | Limited company (trading status) | Trading income, Business Asset Disposal Relief on share sale, IHT business relief |
Switching Costs Between Structures
- Sole trader → Limited company: SDLT at market value (5% additional-dwellings surcharge), CGT deemed disposal (deferrable via TCGA 1992 s.162 if conditions met), refinancing to company BTL products at higher rates, legal and accountancy fees. The detail is in our SDLT on incorporation page.
- Sole trader → Partnership: Cheap if the partnership is genuinely formed (agreement, accounts, joint borrowing). Establishing substance is the cost, not the conveyancing.
- Partnership → Limited company: The reason to run as a partnership in the first place. FA 2003 Sch 15 para 10 reduces the SDLT to nil if the conditions are met.
- Limited company → Sole trader: Rare and expensive. Distribution in specie at market value; company pays corporation tax on the gain, individual pays dividend tax on the distribution. Avoid unless circumstances force it.
- Form 17 split adjustment: Just a new declaration of trust and a new Form 17. Cheap, fast, and reversible at any time.
How MTD for ITSA Tilts the Structure Decision
MTD for ITSA went live on 6 April 2026 for sole-trader landlords with qualifying income above £50,000. The threshold drops to £30,000 from 6 April 2027 and to £20,000 from 6 April 2028. Compliance involves MTD-compatible software (typically £100-£300 a year per business), four quarterly digital submissions, plus a Final Declaration. The official sign-up checker is at gov.uk/guidance/check-when-to-sign-up-for-making-tax-digital-for-income-tax.
Limited companies are outside MTD for ITSA entirely. The compliance cost difference is part of the total-cost-of-ownership maths, especially for landlords sitting just above the threshold.
What About the 2027 "22% / 42% / 47%" Property Income Rates?
The 2% surcharge on property income above the normal income tax rates was announced in the Autumn Budget and is scheduled for 6 April 2027. The provision is in the draft Finance Act 2026 and is expected to complete its parliamentary stages before the start of 2027/28. Until Royal Assent the figures could theoretically still change, but plan on the basis that the current income tax rates (20%, 40%, 45%) apply to property income for 2026/27 and that 22%, 42%, 47% apply from 6 April 2027.
The surcharge strengthens the case for incorporation for higher-rate landlords, because the 22%/42% rates push the personal-tax cost of holding property further above the corporation tax rate. Modelling both rate sets (2026/27 vs 2027/28) is the right way to test the decision before incorporating.
Inheritance Tax and Structure: A Common Misconception
A limited company holding investment property does not qualify for Business Relief under section 105(3) IHTA 1984, because the company's business is wholly or mainly an investment business. The shares are valued at the company's net asset value and the value forms part of the deceased shareholder's estate on death. So a limited company structure is not an IHT shelter in itself.
Where the company structure does help with IHT is in the design of share classes:
- Growth shares issued to adult children at low or nil value capture future appreciation outside the founder's estate.
- Freezer shares retained by the founder fix the founder's IHT exposure to the current company value.
- Discretionary trust holdings of shares can place future appreciation outside the estate, subject to the 10-year and exit charges.
None of these features are available in sole-trader ownership.
The Bottom Line
The most tax-efficient structure for your portfolio depends on five facts about you: marginal tax band, intended hold period, drawn vs retained profit pattern, leverage level, and whether you are part of a couple with mixed earnings. Walking through the four scenarios above with your own figures normally points clearly to one of three answers: sole trader, Form 17, or limited company. LLP and general partnership are usually transitional structures rather than destinations.
The cost of getting it wrong is meaningful: incorporating without need can lock £45,000 of SDLT into a portfolio that did not require it; staying personal as a higher-rate landlord with material mortgage interest can cost £8,000-£15,000 a year forever. A one-off fixed-fee structure review is among the highest-return pieces of tax work a UK landlord can buy.