Joint Ownership and Making Tax Digital — How UK Landlords Should File

By RentVault Team · Published 2026-08-04 · 9 min read

HMRC does not accept a joint MTD submission. Each owner files their own quarterly update, under their own UTR, through their own Government Gateway account. One property, one set of transactions — two entirely separate quarterly filings.

If you own a rental property jointly — with a spouse, partner, family member, or business associate — Making Tax Digital for Income Tax creates a compliance challenge that most landlord software platforms haven't properly solved.

The challenge is this: HMRC does not accept a joint MTD submission. Each owner files their own quarterly update, under their own Unique Taxpayer Reference, through their own Government Gateway account. That means one property, one set of transactions — but two entirely separate quarterly filings.

Most landlord software can tell you that Owner A has a 60% share and Owner B has a 40% share. Very few can automatically generate two complete, separately formatted MTD quarterly export files from the same underlying transaction data — one for each owner, each containing only their proportionate share of income and expenses, ready to submit to HMRC or hand to their accountant.

RentVault does. And it goes further than that.

Why joint ownership and MTD is more complex than it looks

The instinct is to treat joint ownership as simple arithmetic — split the figures by ownership percentage and generate two reports. But the reality is more nuanced, because the legal structure of joint ownership determines how income must be declared to HMRC.

Joint tenants

When a property is held as joint tenants, both owners legally own the whole property together. Neither has a defined share that can be sold independently. For tax purposes, HMRC treats joint tenants as owning equal shares — 50/50 — regardless of any informal arrangement between the owners.

If you and your co-owner are joint tenants, you each declare 50% of the rental income and 50% of allowable expenses, regardless of who paid what or who contributed more to the purchase. You cannot change this without first converting to tenants in common.

Tenants in common

When a property is held as tenants in common, each owner has a defined share that they own outright and can sell, give away, or leave in their will independently. Tenants in common can hold unequal shares — 70/30, 60/40, any split that adds to 100%.

For tax purposes, each owner declares their percentage share of rental income and expenses. A landlord with a 70% share declares 70% of the rental income and 70% of allowable expenses on their Self Assessment return.

Form 17 — the option most landlords don't know about

This is where it gets more interesting — and more valuable.

If you are married or in a civil partnership, HMRC has a default rule: it assumes you own the property 50/50 for income tax purposes, regardless of your actual legal shares. Even if you hold the property as tenants in common with a 70/30 split, HMRC will tax you 50/50 unless you tell them otherwise.

To declare income in proportions that match your actual beneficial ownership, you must file a Form 17 election with HMRC — within 60 days of executing a deed of trust confirming your actual shares.

Why does this matter? Because in many couples, one partner is a higher rate taxpayer and the other pays basic rate tax. If the higher earner holds a smaller share and the lower earner holds the larger share, more of the rental income is taxed at the lower rate. Over a portfolio of properties, the tax saving from a correctly structured Form 17 election can be substantial.

No landlord software platform has, until now, tracked Form 17 elections as a documented event within the platform — or used the Form 17 percentage rather than the legal ownership percentage when generating MTD quarterly exports.

RentVault does.

How RentVault handles joint ownership

When you add a jointly owned property in RentVault, you record each co-owner with their name, National Insurance number, Unique Taxpayer Reference, and ownership percentage. You also record the declaration type — equal shares as joint tenants, unequal shares per deed as tenants in common, or Form 17 election filed.

If you have a Form 17 election in place, you record the Form 17 percentages separately from the legal ownership shares, along with the date the election was filed with HMRC. RentVault uses the Form 17 percentages — not the legal shares — when generating each owner's quarterly export, because that is the basis on which HMRC expects you to declare.

At the end of each quarter, you click Export for all owners. RentVault generates one complete quarterly export file per owner, each containing:

• That owner's proportionate share of rental income for the period
• That owner's proportionate share of each allowable expense category
• Their share of finance costs, presented separately for Section 24 purposes
• The cover sheet showing their name, UTR, the tax period, and — critically — the basis on which the figures were apportioned: per Form 17 election filed on that date, or per beneficial ownership

The files download as a ZIP. Each file is labelled with the owner's name. Each is formatted for their accountant or ready for direct submission to HMRC once RentVault's direct submission capability goes live. Self-employment income is recorded separately on the MTD page using HMRC's SA103 expense categories — kept entirely separate from your rental figures and appearing on its own tab in the Owner Filing Pack.

RentVault also shows a reconciliation on screen before you download: Owner A's figures plus Owner B's figures equal the whole property figures to the penny. You can see immediately that the split is correct before anything goes to HMRC.

What about SPVs and limited companies?

Some portfolios involve mixed ownership — for example, a property owned 40% by one landlord personally, 35% by their spouse personally, and 25% by a limited company or SPV they control.

Each of those ownership interests has a different tax treatment:

• The personal ownership interests are subject to MTD for Income Tax — quarterly updates to HMRC under each individual's UTR
• The company's ownership interest is subject to Corporation Tax — no MTD ITSA requirement, but the company still needs accurate income and expense records for its CT600

RentVault records the ownership structure per property, including SPV and limited company interests alongside personal ownership. The personal owners receive their individual MTD quarterly export files. The company's share is separately recorded for corporation tax purposes — giving the company's accountant a clean income and expense breakdown for their portion of the property without it being conflated with the personal owners' figures.

The Section 24 consideration

For personally owned properties with mortgage finance, Section 24 restricts the deductibility of mortgage interest. Rather than deducting mortgage interest as an expense, landlords receive a basic rate tax credit equal to 20% of their finance costs.

In a jointly owned property, Section 24 applies per taxpayer — each owner's finance cost relief is calculated based on their share of the mortgage interest, not the whole property amount.

RentVault presents each owner's share of finance costs separately on their quarterly export — not as part of the expenses total but as a distinct finance costs figure. This is what their accountant needs to correctly apply Section 24 in the Self Assessment return.

What this means for the 7 November deadline

The second MTD quarterly update deadline for the 2026/27 tax year falls on 7 November 2026. If you jointly own a property and both you and your co-owner are in scope for MTD, that deadline applies to both of you individually. Not sure whether you're in scope? The MTD Readiness Checker will tell you in two minutes.

RentVault's joint ownership export generates both your files from one set of transactions. You and your co-owner each get your own file, correctly apportioned, ready for your individual submissions. You do not need to manually split figures in a spreadsheet or ask your accountant to do it.

For landlords who have been struggling with how to handle joint ownership under MTD — or who have been filing on the assumption that one of them doesn't need to file — this is the practical solution.

A note on Form 17 and professional advice

Form 17 elections and deeds of trust are legal documents with tax consequences. The decision to restructure beneficial ownership, file a Form 17 election, or change the ownership basis of a property should be made in consultation with a qualified accountant or tax adviser. RentVault records the election details you provide and uses them in the export — it does not advise on whether a Form 17 election is appropriate for your circumstances.

If you are unsure whether your current ownership structure is tax-efficient, or whether a Form 17 election might benefit you, RentVault's partner accountants specialise in landlord tax and can assess your position. A first consultation is typically free for RentVault users.

Getting started

If you have jointly owned properties in RentVault, open the property settings and add your co-owner details — name, NI number, UTR, ownership percentage, and declaration type. If you have a Form 17 election in place, record the Form 17 percentages and the filing date.

At your next quarterly export, select Export for all owners. Your co-owner's file is ready alongside your own.

If you are not yet using RentVault, the free tier covers one property with full compliance tracking. Paid plans from £9.99 per month cover joint ownership export, Open Banking bank reconciliation, MTD quarterly exports, and 36 legal document templates.

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This article is for general information only and does not constitute tax or legal advice. Form 17 elections, deeds of trust, and ownership restructuring should be discussed with a qualified accountant or solicitor. Tax rules described are based on HMRC guidance current as of August 2026.