A 12-person accounting firm in Leeds got in touch with EarthOne earlier this year with a problem that has since become familiar across UK practices. A meaningful share of their client base, self-employed traders, small business owners, landlords with rental income, had crossed the point where HMRC now wants updates from them several times a year instead of once.
Nothing about the client list had changed. The same clients who filed one Self Assessment return every January were suddenly generating four to five deadlines a year under Making Tax Digital for Income Tax. The work had not gotten more complex. It had simply started repeating.
By April 2026, HMRC estimates 864,000 sole traders and landlords with qualifying income over £50,000 became mandated into MTD for Income Tax. A further 1,077,000 in the £30,000 to £50,000 band join from April 2027, and another 975,000 follow from April 2028 as the threshold drops to £20,000. Within three years, close to three million taxpayers move from one annual filing to a minimum of four quarterly submissions plus a year-end declaration.
For the firms holding these clients, that is not really a compliance change. It is a capacity problem wearing a compliance disguise. This article looks at what actually happens inside a practice when a chunk of its client base multiplies its filing frequency, why hiring rarely fixes it fast enough, and how one firm restructured the work instead of the team.
It Wasn't New Clients. It Was the Same Clients, Four Times a Year
Most explanations of MTD for Income Tax focus on the rules: who qualifies, which software is compatible, when the quarterly windows fall. Firm owners mostly know the rules by now. What the compliance guides skip is what the rule change does to a practice's internal capacity, and it is worth stating plainly.
MTD for Income Tax does not increase the number of clients a firm serves. In most cases it does not increase the technical complexity of any single client's affairs either. What it does is take a task that used to happen once a year per client, gathering receipts, categorising transactions, reconciling bank feeds, and makes it happen four or five times a year instead.
A firm with 40 clients newly mandated into quarterly filing has not taken on 40 new clients' worth of work. It has taken on something closer to 160 filing events where it previously had 40. The clients are identical. The relationship management is identical. The only thing that changed is how often the same routine task has to be assembled, checked and submitted.
That distinction matters because it changes what the fix looks like. A firm that treats this as "more clients" reaches for recruitment. A firm that recognises it as "more repetitions of the same task" should be looking at how that task gets produced, not who else needs to be hired to produce it.
The MTD Calendar Firms Are Now Working Against
MTD for Income Tax requires affected sole traders and landlords to keep digital records and send HMRC a quarterly update of income and expenses, followed by a final declaration once the tax year ends. The legal obligation sits with the taxpayer, but in practice it is almost always the firm doing the record-keeping and the submission on their behalf.
The rollout is phased by income:
| Qualifying income | Mandated from | Estimated taxpayers affected |
|---|---|---|
| Over £50,000 | April 2026 | 864,000 |
| £30,000 to £50,000 | April 2027 | 1,077,000 |
| £20,000 to £30,000 | April 2028 | 975,000 |
For a client mandated from April 2026, the quarterly submission dates for the 2026-27 tax year fall on 7 August, 7 November, 7 February and 7 May, each one month after the quarter it covers ends. Add the year-end final declaration and a firm is now managing five HMRC touchpoints a year for a client who used to generate one.
There are no penalties for a missed quarterly update in the 2026-27 tax year itself. HMRC has confirmed a penalty-free settling-in period for the first year of mandation. From 2027-28, a points-based penalty regime begins, with a fixed £200 penalty once four points accumulate. That grace period will not last, and firms that use it to postpone restructuring their workflow will run out of runway at exactly the moment the next threshold, and the penalties, both land.
Inside a 12-Person Firm: Where the Extra Filings Actually Landed
The Leeds firm is a useful illustration because its situation was not unusual. The firm ran well. Client relationships were strong. The team was competent. The constraint was not a management failure. It was structural: too much of the same low-value task landing on too few people, repeatedly.
Every few months meant chasing the same missing receipts from the same clients again. Bank feeds needed reconciling on a fixed schedule instead of once a year. And the people doing that chasing were, more often than not, the firm's two senior accountants, the ones clients actually went to for real advice.
That is the part firm owners tend to underestimate. Quarterly MTD work does not sit neatly with junior staff by default, because a firm that has not built a dedicated production process ends up routing new, unfamiliar work to whoever already understands the client relationship. In a 12-person firm, that usually means the seniors.
A missed receipt chased once a year is an inconvenience. The same missed receipt, chased four times a year, by the same senior accountant, is a recurring tax on the exact people a firm can least afford to have doing repetitive admin.
Hiring was the obvious next move, and also the slowest one available. Qualified accountants are scarce in the current UK market, and a new hire typically takes two to three months to become independently productive, longer if the role involves client-facing judgement. A firm feeling the pressure in one quarter cannot wait three more for a new starter to become useful.
The Mistakes Firms Make When Volume Increases, Not Complexity
Watching firms go through this transition, the same missteps come up repeatedly.
Treating quarterly work as a smaller version of annual work. It isn't. Annual work has slack built in. If a client is a week late with receipts in January, the actual deadline is still months away. Quarterly work has almost no slack. A client who is a week late in August has already eaten a meaningful share of the window before the November deadline.
Hiring reflexively instead of restructuring first. Recruitment is the instinct, but qualified staff take months to source and longer to become productive. A firm that hires without first separating routine production work from client-facing advisory work simply creates a second person doing the same undifferentiated job the seniors were already doing.
Assuming any new resource has to sit inside the building. Firm owners often rule out outsourcing before evaluating it, assuming it means losing oversight of the work. In practice, a dedicated outsourced team working inside the firm's existing software, on the firm's existing client files, changes who does the production work. It does not change who owns the client relationship or signs off the final numbers.
Waiting to see how bad it gets before changing anything. The 2026-27 penalty-free year makes this mistake look cheap. It isn't. The workload cost of quarterly filing exists whether or not HMRC issues a penalty for a missed deadline. Waiting for the points-based penalties to start in 2027-28 to fix a process gives a firm one more mandated cohort, the £30,000 threshold and its 1,077,000 taxpayers, to absorb at the same time.
A Framework for Absorbing Quarterly Volume Without Losing Your Senior Team
The change that worked for the Leeds firm, and the pattern EarthOne sees repeated across firms handling this well, comes down to separating two categories of work that had previously been bundled inside the same person's day.
- Map which clients are newly mandated, and when. Cross-reference client turnover and rental income against the £50,000 threshold now, then the £30,000 threshold before April 2027. Know the number before it arrives as a surprise.
- Separate production from review. Data entry, receipt chasing, bank reconciliation and draft quarterly figures are production work. Checking the draft, resolving judgement calls and talking to the client about what the numbers mean is review work. These do not need to be done by the same person.
- Build a dedicated team for the production layer, not a shared pool. A ticketing system that routes work to whoever is free tends to reproduce the same bottleneck under a different name. A named team that works the same hours, inside the same software, learning the same clients quarter after quarter, gets faster with each cycle instead of starting cold every time.
- Keep sign-off with your own qualified staff. The firm's own team reviews and approves every submission before it goes to HMRC. Outsourcing the production step does not mean outsourcing professional responsibility for the number that gets filed.
- Reassess after one full quarterly cycle. The first quarter under a new structure is calibration. By the second, briefing templates and review checklists should make the handoff close to routine.
Feeling the MTD workload before the £30,000 threshold even lands?
Speak to a qualified CA about which parts of your clients' quarterly filing work could move to a dedicated offshore team, without changing who signs off the numbers.
Book a free 30-minute consultationWhy the Fix Was Structural, Not Just More Hands
Outsourcing was not valuable here because offshore labour costs less than a UK hire, although it usually does. It was valuable because it removed the capacity constraint at the exact point where hiring is slowest to help. A dedicated team led by qualified Indian Chartered Accountants, working the Leeds firm's own software and the same hours, took over the quarterly production work: pulling together the numbers, keeping the books current, doing the reconciliation groundwork. The firm's own senior accountants kept the part that actually needed them, checking the output and signing it off.
The work itself did not shrink. It moved off two people's desks and into a team built specifically to handle repetition well. A few months in, the senior accountants who had been chasing the same receipts every quarter were back to the client conversations that justify their qualification. The firm's founder was satisfied enough with the result to introduce two other Leeds-area firms carrying the same MTD-driven capacity problem.
That referral pattern is worth noting on its own. Firm owners rarely recommend a supplier for a compliance headache. They recommend one for giving their best people their time back.
What to Do Before the Next Threshold Drops
April 2027 brings the £30,000 threshold and roughly 1,077,000 more taxpayers into MTD for Income Tax. Firms already stretched at the £50,000 tier will feel that cohort land on top of an existing constraint, not into a clear system.
The practical first step is the one the Leeds firm took: work out how many current and prospective clients sit in the next threshold band, and decide now which parts of their quarterly filing is production and which is review. That distinction determines whether the answer is hiring, restructuring, outsourcing, or some combination of the three, before the deadline decides it for you.
EarthOne works with UK accounting firms building exactly this kind of dedicated production team ahead of MTD deadlines. Published pricing is on the website, no discovery call required to see what it costs. The for-firms page explains how the dedicated team model works day to day, and a free 30-minute consultation is the fastest way to map your own threshold exposure.
