The number that changed how I think about software came from one household. A couple I act for jointly own three UK properties and a Spanish apartment, and one of them runs a self-employed consultancy.
If both owners are in scope for MTD for Income Tax, they don't file once a year each. HMRC requires quarterly updates for each self-employment and property business. UK property is one business and foreign property is another, so each owner sends four updates for UK property and four for foreign property, and the self-employed owner sends four more. That is 20 quarterly updates a year plus two tax returns, 22 submissions in all.
Multiply that across the few hundred landlords and sole traders on my books, and the question stops being how to file. It becomes which platform can carry the volume without a second subscription, a spreadsheet workaround, or a missed deadline.
What most practices still have not settled is what to run it on. That one choice quietly sets everything after it: the hours each client costs you, whether your team copes with four update deadlines and a return deadline every year, and whether the fee you quote today still works three years from now.
I run a property tax practice with thousands of clients and built the platform we use to manage them, so what follows is the evaluation I wish someone had handed me before I locked any of it in.
For the regime itself, our main MTD ITSA guide carries the detail.
MTD for Income Tax in Brief: Which Clients Need Software, and When
Software selection starts with scope. HMRC assesses each individual’s qualifying income, and the thresholds step down over three years.
Qualifying income | Based on the tax return for | Start date |
|---|---|---|
More than £50,000 | 2024 to 2025 | 6 April 2026 |
More than £30,000 | 2025 to 2026 | 6 April 2027 |
More than £20,000 | 2026 to 2027 | 6 April 2028 |
Qualifying income is total turnover from self-employment and property before expenses, taken from the previous year’s Self Assessment return. It is not profit. For a UK-resident client, it includes foreign property. A share of a jointly let property counts. Employment income, dividends, pensions and an individual partner’s share of partnership profit do not. £25,000 of rent plus £27,000 of self-employment income gives £52,000. Partnerships do not yet need to use MTD for Income Tax, and HMRC has said it will set out the timeline later.
Three practical points:
HMRC writes to clients it believes are in scope, but if no letter arrives, the taxpayer is still responsible for checking.
Exemptions exist, some automatic and some by application. HMRC will not accept a digital exclusion application only because a client is unfamiliar with software or has few records.
Clients whose return includes the SA109 supplementary page have a temporary exemption for 2026/27 (automatic if the page was on the 2024/25 return, otherwise by application). They may need to start from 2027/28 if qualifying income is above £30,000.
What HMRC Says Your Software Must Do
GOV.UK says you, or your agent, must use commercial software to create, store and correct digital records, send quarterly updates and submit the tax return, including any other income sources. You can use one product or several that work together, but only one product for each separate submission. HMRC publishes a software finder, says every listed product has been through its recognition process, and recommends no product. It also says to check that software supports all your income sources, works with your accounting period, reports your other income and, where relevant, allows multiple agents. Free products exist but may carry limits, such as a cap on transactions.
GOV.UK’s current guidance calls the year-end step submitting your tax return. Earlier HMRC guidance called it the final declaration, and you will still see that term in software. This guide uses “tax return”.
Ten Questions to Ask While Evaluating an MTD Software
Rather than comparing products feature by feature, put these ten questions to any MTD platform on your shortlist. The answers tell you whether it can run your practice or just file individual returns.
# | Question | Why It Matters | Basis |
|---|---|---|---|
1 | Does it cover all your clients’ income sources (self-employment, UK property, foreign property)? | GOV.UK says software must support all of them; otherwise you need a second product that works with it | HMRC |
2 | Does it handle joint ownership, with your share held per property? | Only your share goes into your records, and HMRC lets you choose whether to include expenses for jointly let property in quarterly updates. Manual split calculations every quarter do not scale | HMRC and Practice |
3 | Can it flag restricted finance costs (often called Section 24) when a record is created? | HMRC’s guidance says residential landlords using simpler categorisation must still record whether an expense is a restricted finance cost, so check how the software captures this. Doing it at entry rather than at quarter-end is our recommendation | HMRC and Practice |
4 | Does it import letting agent statements (PDF or CSV)? | Statements are a regular data source for agent-managed properties | Practice |
5 | Does it support quarterly updates and the tax return, or does a second product cover the return? | Both must go through compatible software; separate products are allowed if they work together | HMRC |
6 | Does it show every client’s status and deadlines in one view? | Without it you manage the regime one client at a time | Practice |
7 | Does it support bulk information requests and client approval workflows? | Manual chasing does not scale, and a recorded approval supports your engagement terms | Practice |
8 | Does it keep separate records for each foreign property and handle currency? | HMRC requires separate digital records for each foreign property, which then form one foreign property business | HMRC and Practice |
9 | Can you submit to HMRC from the platform under your agent authorisation? | Updates and returns must go through compatible software; a manual export-and-upload step adds time | HMRC and Practice |
10 | Does it support the main or supporting agent role you will hold? | The roles have different access | HMRC |
If the answer to any of these is no, you have found a gap that will cost you time, money, or both across the quarterly cycle.
The Software Test
Rather than comparing products feature by feature, run each shortlisted product through four tests. Together they show whether a platform can run your practice or only file individual returns. Tests 1 and 4 rest mainly on HMRC guidance. Test 2 is practice advice, and Test 3 combines HMRC’s deadlines with practice advice.
Can It File UK Property, Foreign Property and Self-Employment on One Client Record?
This is the first test, and it is where most selections go wrong. The practice evaluates the platform against its simplest clients, confirms it works, and rolls it out. Six weeks later it meets the client with a Spanish apartment, the couple who own 70:30, or the sole trader who also lets a flat, and the platform cannot file them in one place.
GOV.UK says your software must support all of a client’s income sources. HMRC’s software finder lets you filter by the income sources a product supports, so check each product’s listing rather than assuming that handling one income source means handling the others.
Check on the Finder | Why It Matters |
|---|---|
Self-employment, UK property, foreign property | Software must support every income source the client has |
Quarterly updates and tax return | Both are required, though possibly from different products |
Reporting other income on the return (including a partner’s profit share) | The return must include all other income sources |
Standard or calendar update periods | Software must work with the client’s accounting period |
Multiple agents | Supports a main agent plus supporting agents |
Free-tier limits | Free products can cap transactions |
If one product cannot cover every income source, you can choose another or use more than one. HMRC allows several products, for example one per income source, or one for records and updates and another for the return. You can use only one product for each separate submission, and records must be digitally linked between products. In practice that can mean two subscriptions, two sets of records and two workflows for the same client. That is manageable for a few clients and harder across a practice, so decide before you shortlist.
Before you shortlist anything, audit your client base for multi-source clients. If a meaningful proportion of your landlord clients also have self-employment income, or any have foreign property, you need software that covers all three, or a clear plan for running two products per client and absorbing the cost.
Can You See Every Client and Every Deadline in One View?
A platform that shows you one client’s position is a client tool. The one you need shows every client’s position across every quarter. That is the difference between a bookkeeping product and a platform built to run a practice.
Here is what a practice-grade MTD dashboard should give you:
Status across your client base
Every MTD client visible at once, with a status for each: Not Started, Information Requested, In Progress, Awaiting Approval, Filed. An “Overdue” flag overlays any status where the deadline has passed.
Deadline tracking and risk flags
What is due this week, this month, and what is overdue, sortable by deadline, status, team member and client type.
Bulk information requests
After each quarter-end you need to confirm every in-scope client’s data is complete. From a dashboard that can be one templated, tracked request instead of one email per client.
Client approval workflow
HMRC’s guidance makes clients responsible for the accuracy of records where bank feeds are used. A structured approval with a secure link and timestamp is a sensible way to document that, and ICAEW notes that engagement letters will need updating for MTD.
Direct HMRC submission
Quarterly updates and the tax return filed from the platform, with no manual step between review and submission.
If your shortlisted software does not offer practice-level visibility across the entire client base, you are managing the regime blind. That holds up in the first quarter, when volumes are low, and goodwill is high. It does not hold up in the third, when the novelty has worn off, and the deadlines keep coming.
Does It Run the Quarterly Cycle, or Just File the Return?
Filing is the easy part. The work that breaks practices is everything around it: chasing the data, reviewing it, getting the client to approve it, then doing that for the whole book, four times a year. HMRC’s deadlines are 7 August, 7 November, 7 February and 7 May, for update periods ending 5 July, 5 October, 5 January and 5 April. Each update is cumulative from 6 April, and you must still send a nil update. The table below is a suggested internal schedule, not an HMRC requirement.
Stage | When | Who | What happens |
|---|---|---|---|
Data capture | Ongoing through the quarter | Client and automation | Bank feeds, letting agent imports and receipt scanning populate the software continuously |
Data cut-off and chase | Week before quarter-end | Firm | Client receives a checklist, outstanding items are flagged, reminders are sent |
Review and categorisation | Week after quarter-end | Bookkeeper | Transactions reviewed, exceptions queried, uncategorised items resolved, restricted finance costs segregated |
Senior sign-off | Days 10 to 14 after quarter-end | Manager or partner | Draft reviewed, signed off or queried |
Client approval | Days 14 to 28 after quarter-end | Client | Client receives a draft summary, confirms or queries, authorises submission |
File and confirm | Before the filing deadline | Firm | Quarterly update filed, receipt captured, client confirmation sent |
Three Rules That Keep You Ahead of the Filing Deadline
Work starts before the quarter ends, not after: If your team’s first look at a quarter’s data is on 6 July, the 7 August deadline is already under pressure. The data cut-off chase should start in the last week of the quarter. Clients appreciate fewer last-minute asks, and firm-side capacity is smoothed across a longer window.
The deadline is internal, not external: Treat HMRC’s 7th-of-the-month deadline as the last possible day, not your target. For 2026/27, HMRC will not apply penalty points for late quarterly updates, but you still must submit them before you can submit the return. From 2027/28 each missed update deadline earns a point, and at four points a £200 penalty applies, with a further £200 for each later miss. Set the firm’s internal deadline five to seven days earlier and use the buffer for the inevitable client who goes quiet for a fortnight. The firm that files on the 2nd or 3rd has capacity to spare. The firm that files on the 7th has none.
Client approval is a step, not an afterthought: Every quarterly update should be reviewed by the client before filing, which protects the practice as much as the client. A structured approval workflow, with a secure link and a timestamped record, is the fastest way to close the cycle.
Can It File in Both Main and Supporting Agent Roles?
MTD lets a client appoint one main agent and any number of supporting agents, with different levels of access, so your platform needs to work in whichever role you hold.
The main agent can do almost everything the client can do online, including finalising the tax return and viewing tax calculations. It cannot set up a Direct Debit or change how HMRC contacts the client. The supporting agent has limited access to business and property income details. It can create records, send quarterly updates and contact HMRC about the client’s sole trader and property businesses. It cannot contact HMRC about the client’s tax returns, view the tax calculation or non-business income, finalise the client’s position or submit the tax return. Copies of late-submission and late-payment penalty notices go to the main agent, not the supporting agent, which matters when your firm sends the quarterly updates while another firm holds the main agent role.
To act, an agent needs an agent services account and the client’s authorisation, and the consent the client sees differs for the main and supporting roles. If more than one agent works on the same business, one combined update must be sent for each update period and for the return after adjustments, so agree who owns which step.
Opportunity for a Specialist Accounting Firm
A property bookkeeping practice can offer a supporting agent service, handling the quarterly update mechanics for other firms’ clients, while the primary accountant keeps the main agent role for the year-end and advisory work. The supporting agent handles the volume; the main agent handles the complexity.
For illustration only, using hypothetical figures: 100 quarterly-update-only clients at £600 a year each would generate £60,000 of annual fee income. The margin per client is lower than a full-service engagement, but the time per client is far less.
If you are a generalist practice that does not want to build a quarterly property workflow, the supporting agent model gives you a referral route. If you are a specialist property firm, it gives you a new revenue stream. Either way, check the platform can file in the role you intend to hold.
Six Software-Selection Mistakes That Cost You Every Quarter
A few selection mistakes show up again and again. Each one costs time every quarter, for every client.
Choosing software on what your existing platform already does, rather than on whether it handles property natively, foreign property, and joint ownership without manual workarounds.
Evaluating the software against your simplest client instead of your most complex one. The platform that handles the couple with five properties at mixed ratios, a foreign apartment and self-employment income is the one that scales.
Treating the multi-client dashboard as optional. This feature decides whether you manage the regime at practice level or one client at a time.
Leaving the workflow design until after the first quarter, when the team is already scrambling.
Assuming all MTD software is equivalent. Check each product’s listing on HMRC’s finder for the income sources and submission types you need.
Pricing MTD as Self Assessment with a small uplift. Each client now has four quarterly updates for each business plus a tax return, so build the extra touchpoints into your fee.
Why “MTD-Ready” Software Does Not Mean Ready for Your Practice
Vendors describe products as MTD-ready, and HMRC’s finder shows which have been through its recognition process. Neither tells you whether a product fits your practice. The real question is narrower: can this platform carry your whole client book through four quarters and a year-end without manual workarounds? Being able to submit one quarterly update to HMRC is the entry ticket. It is not what separates a platform that runs your practice from one that files a single return.
Three capabilities decide that:
Every income type in one client record: UK property, foreign property and self-employment, without forcing you onto a second platform for mixed-income clients. A landlord who also runs a sole trade, or a sole trader who also lets property, falls into a gap that many platforms cannot bridge.
Property accounting handled natively: automatic joint ownership splits at any ratio, restricted finance cost (Section 24) categorisation at the point of entry, per-property profitability, letting agent statement imports, and foreign property with per-property records and currency conversion. These are the core mechanics of property tax under MTD, not optional extras.
Practice-scale operation: a multi-client dashboard showing every client, every quarter, every deadline. Bulk information requests. Client approval workflows. Review and sign-off sequences. HMRC filing from the dashboard. Status across the entire client base, not one client at a time.
MTD for Income Tax changes how income and expenses are recorded and reported. Clients still submit one tax return for the year and pay their tax bill as they do now, with the return due by 31 January. What changes is the record-keeping and the reporting rhythm. A practice that used to touch each client’s file once a year will now touch it at least five times, four quarterly updates plus the return for each business. Every workflow inefficiency in the annual model is multiplied, which is why the platform you choose matters.
Where RentalBux Fits This Checklist
I want to be transparent about this section. RentalBux is the platform I built for my own practice, so I have a commercial interest, and I am naturally going to think it is a good answer. Judge it, like any product, against the ten questions above and against HMRC’s software finder, which is where you should confirm which income sources and submission types any product currently supports. HMRC recommends no product.
To see how RentalBux handles your own client mix, book a practice walkthrough or see current plans.
Before You Choose Anything, Audit Your Client Base
If you take one thing from this guide, make it the client-base audit. Count the income types, the joint owners, the foreign properties and the clients who file the SA109 page in your book. Thresholds apply to each individual, so check each owner separately. Check exemptions too, including the temporary 2026/27 exemption for SA109 filers.
That audit tells you what your software actually needs to do, and it is the input to both your workflow design and your pricing. Most platforms that looked adequate before the audit look inadequate after it.
Then run a dry quarter with your ten most complex clients before you roll out to the full base. The mistakes you catch in a dry run are the ones that would otherwise cost you money in a live quarter. The next update deadlines are 7 November 2026 and 7 February 2027. HMRC will not apply late-update penalty points in 2026/27, but the updates are still required.
