Best Self-Assessment & MTD Software in 2026: Expert Review for Accountants, Sole Traders & Landlords

Tax Queen

Tax Expert @ Pie

10 min read

This article reviews the best Self Assessment and Making Tax Digital software available in the United Kingdom in 2026, for sole traders, landlords, self-employed people and the accountants who act for them. It explains what changed on 6 April 2026, compares the three types of software now on the market, and sets out which suits filing direct to HMRC and which is built for practices. It covers the quarterly update cycle, the record-keeping bottleneck that catches most people out, the deferrals and exemptions that mean some clients are still outside the regime, and the penalty position for the first mandated year.

Why Choosing Self-Assessment Software Got Harder in 2026

For roughly two decades this was a settled question. You kept a spreadsheet, or your accountant did, and an SA100 went in before 31 January.

That model ended on 6 April 2026. Sole traders and landlords with combined gross income from self-employment and property above £50,000 in the 2024/25 tax year are now inside Making Tax Digital for Income Tax, unless they are exempt or sit in one of the deferred groups covered further down. The threshold falls to £30,000 from April 2027 and to £20,000 from April 2028.

The practical effect is that a once-a-year job became a quarterly one. Four updates per business, then the final return. Someone who trades and also lets property files a separate update for each source every quarter, so the count is nine submissions a year rather than five.

Two things follow from that. Software that only produces an SA100 in January is no longer enough, and the free HMRC filing route many people used is no longer available to them once they join. Once you are in, your year end return has to go through compatible software, and so does your agent's if you use one. Our guide to Making Tax Digital for sole traders and landlords covers the underlying rules.

The 3 Types of Self-Assessment Software Options Compared

The market has split into three groups that look similar in advertising and are built for completely different people. Buying from the wrong group is the most expensive mistake available here.

1. Practice Compliance Suites (Built for Accounting Firms)

These are the tools accountants use to file on behalf of hundreds of clients. They are priced, licensed and designed for that.

TaxCalc is the most common answer for small and mid-sized practices, covering the full return set with a check and review layer and a practice manager tying client records together.

IRIS Personal Tax is the incumbent in many established firms, with deep supplementary page coverage and integrations across Xero, QuickBooks, Sage and Microsoft 365.

Bright and Absolute are the value options. BTCSoftware now sits within the Bright group and is being superseded by BrightTax, its cloud successor, so a practice buying today is buying BrightTax. The Foreign (SA106) and Residence (SA109) schedules are only in BrightTax for 2025/26. Both firms sell practice management separately, as BrightManager and Absolute Practice Manager.

Digita sits at the top of the market and earns its cost where there is high volume genuinely complex personal tax work.

If you are a sole trader or landlord, none of these are for you. They are agent tools, they assume an agent services account, and they are sold on a per-practice basis.

2. Traditional Cloud Accounting (Built for Larger SMBs)

Xero, QuickBooks, Sage and FreeAgent were built for businesses with invoicing, payroll, VAT and a bookkeeper.

They are capable, and if you already run one for a business with staff, adding the tax layer makes sense. Xero Tax, for example, removes rekeying where the client base already lives in Xero.

The mismatch is that most sole traders and landlords are buying a full accounting system to solve a tax problem. You end up configuring a chart of accounts to file four updates a year, paying for invoicing and payroll modules you never open, and doing bookkeeping in accounting language rather than tax language.

3. Modern Direct Tax Apps (Built for Sole Traders & Landlords)

This category exists because of Making Tax Digital. The premise is different: start from the tax return rather than from the ledger.

Pie sits here. It connects to your bank through open banking, categorises income and expenses as they land, shows your tax position in real time rather than as a January surprise, and files quarterly updates and the final return direct to HMRC. There is no chart of accounts to build and no accounting setup to get wrong.

The practical difference is where the effort sits. A cloud accounting package asks you to do bookkeeping and then produces tax figures. A direct tax app tracks the tax figures and asks you to confirm them. For someone whose whole reason for being here is a legal obligation rather than a desire to run management accounts, that is the right way round.

It works on desktop and mobile, which matters more than it sounds. Quarterly deadlines fall on the 7th of August, November, February and May, and the expenses that get missed are the ones incurred away from a desk.

The Client-Side Record-Keeping Bottleneck: How Accountants Solve It

Here is the part nobody budgeted for.

Every practice suite above is competent at producing a return. None of them solves the actual constraint, which is getting 50 or 200 clients to keep digital records continuously rather than posting a carrier bag of receipts each January.

Quarterly filing makes that constraint four times worse. An accountant cannot rebuild a year of records four times a year at a price anyone will pay.

So a growing number of firms now run a two layer stack. A compliance suite at the practice end for preparation and filing, and a client-facing app at the other end that captures income and expenses at source so the quarterly update becomes a review rather than a rebuild.

Pie is built for that second layer. The client keeps their own records without needing to understand double entry, and the agent receives reconciled data at each quarter end. Whether the client then files themselves or hands over to the agent, the underlying records are already in the state HMRC requires.

You can see the workflow on the how it works page, and the reasoning behind the approach on why Pie.

Understanding MTD for ITSA Requirements & 2026 Deadlines

Four requirements apply once you are in.

Keep digital records of income and expenses as they arise, not reconstructed later.

Send a quarterly update for each business source by the 7th of August, November, February and May.

Submit a final declaration by 31 January following the tax year, which replaces the old Self Assessment return.

Use software with a digital link all the way through, meaning no manual retyping between systems. Our Making Tax Digital hub sets out what each of those four looks like in practice and how Pie handles them.

For agents, there is a step before any of this. Your firm needs an agent services account, and it gets exactly one, linked to the firm's UTR. Existing authorisations transfer across in bulk rather than one at a time, and new clients are added through the digital handshake as either a main or supporting agent. That distinction matters, because a supporting agent can keep records and send quarterly updates but cannot file the return, and only the main agent receives penalty information.

Our guides to the HMRC agent services account and registering an agent code cover both routes, and clients can read about authorising an accountant with HMRC.

ICAEW suggests allowing around 4 minutes per client for the sign up itself. Across a 200 client list that is more than a full working day, so it does not belong in the same week as a deadline.

Elder client talking to his account on AML compliance

Soft Landings vs. Late Filing Penalty Points in Year One

For 2026/27, no penalty points apply to late quarterly updates. Two limits on that. It does not extend to the final return or to payment, and it applies only to those mandated from April 2026, not to the cohorts joining in April 2027 and April 2028.

From 2027/28 the points system applies fully. Each missed deadline is 1 point, and at 4 points a £200 penalty is charged, with a further £200 for every subsequent late submission while at the threshold. A missed deadline costs one point however many updates were late against it. Points below the threshold expire automatically 24 months after the deadline missed. Once you reach four they stop expiring individually, and clearing them requires 12 months of on-time submissions plus every outstanding update and return from the previous 24 months.

Late payment sits outside the update easement, with a concession of its own. It applies to balancing payments, amendments, and assessments, not to payments on account. Under HMRC’s harmonised penalty regime, the charge is a 2% penalty on tax outstanding at day 15, and a further 2% on anything still outstanding at day 30 (making 4% total). From day 31, a second penalty accrues at an annualized rate of 4%, calculated daily. In the first year of mandation, HMRC applies a soft landing by giving you 30 days rather than 15 to pay or agree to a Time to Pay arrangement before penalties trigger, though that 30-day window is a one-time concession per taxpayer.

There is also a penalty of up to £3,000 per failure for not keeping digital records or for breaking a digital link between systems, such as copying figures by hand from a spreadsheet into filing software. There is no mechanism to charge it automatically, so it surfaces during an enquiry rather than as routine exposure. Our guide to the penalty points system for late returns sets out how this sits alongside the older regime.

Expert Verdict: Building the Ideal Accountant-Client Software Stack

There is no single best answer, because it depends which side of the relationship you are on.

If you are a sole trader or landlord filing yourself, you want a direct tax app. Bank feeds, real time figures, quarterly updates and the final declaration in one place, on a phone as well as a laptop, without an accounting system underneath it.

If you are a sole trader or landlord who uses an accountant, you still want the client-side app. Your accountant's compliance suite does not capture your receipts, and the quarterly cycle means somebody has to. Doing it as you go is cheaper than paying for it four times a year.

If you are a practice, the compliance suite you already run is probably the right one. TaxCalc suits firms under about 250 clients, IRIS firms are better off staying put than migrating mid transition, a Xero heavy list is well served by Xero Tax, and high volume complex personal tax still justifies Digita. The decision that actually matters is what you put in front of clients.

What none of the practice tools fixes is client behaviour, and that is where the second layer earns its keep.

Abstract image for Correcting Post Filings

Should Clients File Directly or Work With an Accountant?

Filing directly makes sense where the position is straightforward. One or two income sources, ordinary expenses, no unusual reliefs, no property disposals. With software that files direct to HMRC, the quarterly updates are a few minutes each and the final declaration is a confirmation exercise. See what Self Assessment is if you are new to it, and how to file your UK tax return for the process.

An accountant earns their fee where there is genuine complexity. Capital gains, foreign income, a business changing structure, an HMRC enquiry, or a judgement call about what is deductible. See the essential role of accountants for where that value sits.

The choice is not binary, and the sensible middle is common. You keep your own records in an app, and your accountant reviews and files. That is cheaper than full bookkeeping, more reliable than a shoebox, and it satisfies the digital records requirement either way.

Frequently Asked Questions

Do I need new software if I am below the threshold?

Not immediately, but the threshold falls to £30,000 from April 2027 and £20,000 from April 2028, so most sole trader and landlord lists are caught within 24 months.

Are any people above the threshold still outside MTD for now?

Yes. A one year deferral to April 2027 applies to those with trust or estate income, those claiming averaging adjustments, those claiming qualifying care relief, those who need to file non-residence SA109 supplementary pages, and visiting performers meaning non-UK resident entertainers and sportspeople. Those under Court of Protection deputyship or acting under power of attorney are permanently exempt, as are people without a UK National Insurance number on 5 April before the tax year. The deferrals most often missed on a first pass are farming, foster care and landlords living abroad who file SA109.

Can I still file through the old route?

For the tax year before you join, yes. Once you are inside, the year end return must go through compatible software, and so must your agent's. The MTD for ITSA deadlines guide sets out the cut over.

How do I check software is genuinely recognised?

HMRC no longer publishes a table. It runs a software finder that asks a short set of questions and returns a personalised list, with each product page setting out which income sources are ready and which are still in development. Check the specific return types you need, and check quarterly update support separately from annual filing support.

When should I switch?

Not in January, and not in the fortnight before a quarterly date. With the 7 August update behind us and 7 November next, the realistic windows are late August into September, and again from late November.

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