MTD at scale: the pilot insights that matter
Making Tax Digital (MTD) for Income Tax submissions now take a few minutes. But the efficiency didn’t just come from the filing step. The MTD for Income Tax pilot ran the regime under real deadlines, real client data, and live HMRC interaction. What emerged was clearer than any guidance document could show: managing quarterly submissions across multiple clients requires workflow design, resource planning, and knowing where bottlenecks actually sit.
For firms preparing for mandation, the pilot exposed what happens when volume and timing collide. Sai Anaparthy, Senior Product Manager at Thomson Reuters® responsible for the Digita MTD for Income Tax delivery, describes it as an experience defined by how firms, software and HMRC systems work together under live conditions. The insights that followed shaped not just the software, but how firms are structuring their approach to the new MTD regime.
Complete onboarding before the submission deadlines arrive
One of the clearest lessons from the pilot: onboarding takes longer than expected and doing it under deadline pressure creates avoidable disruption.
With submissions starting in July 2026, firms have a narrow window to learn from what pilot firms discovered.
As Sai explains “Getting the setup right before using the software makes a lot of difference, That includes signing up clients for MTD, checking for any exclusions for clients who can be excluded from MTD for 2026/27 tax year, setting up Agent service account, transferring agent authorisations and completing the digital handshake within the software.”
Complete your onboarding process now, while you have time to troubleshoot, rather than in the weeks before your first quarterly update deadline.
Efficiency builds as familiarity grows
As firms progressed through the pilot, workflows became more established. “In the early stages, we saw submissions taking over 20 minutes,” Sai says. “As the workflow became clearer and more familiar, and with the introduction of functionality allowing users to save mappings to tax categories, the time required to complete a quarterly submission reduced significantly. By Q3 of the pilot, users were able to submit in under two minutes in most cases—representing a 10x improvement in efficiency. This is where the real value lies, particularly for firms managing submissions across multiple clients.”
As firms moved further into live use, more complex scenarios began to emerge.
“Sandbox environments are useful, but they cannot reflect what happens with real data and live HMRC interactions,” Sai says. “Calendar election was one example, where firms align reporting periods differently to the tax year. That affects how submissions are handled. We had to respond quickly, because those are not things you can fully anticipate in advance.”
Pilot firms played an active role in refining the process.
“We worked very closely with pilot customer firms, and that shaped a lot of the improvements we made,” Sai notes. “Those firms were working through a new regime in real conditions, often without a clear reference point. That input was critical in helping us understand where processes needed to be clearer.”
That collaboration led to practical changes, particularly around spreadsheet handling and data mapping, where firms match existing records into the format needed for submission.
“The focus was on reflecting how firms already work, rather than expecting them to standardise everything.”
Throughout the pilot, firms operated within a system dependent on HMRC services.
“There were instances where submissions did not behave as expected,” Sai notes. “In those situations, the key is understanding where in the MTD ecosystem the issue sits, whether that sits within the workflow, the submission, or the interaction with HMRC. That visibility helps firms respond more effectively.”
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Managing MTD alongside peak deadlines
January brought the resourcing challenge into sharp focus, combining self-assessment work with Q3 submissions.
“That overlap gave a clear picture of how timelines interact under MTD,” Sai reflects. “It led firms to think more carefully about allocation of work, what sits with the client, and how activity is spread across the year. It becomes part of planning, not just compliance.”
This is where the shift from annual to quarterly becomes tangible. MTD adds four submissions to the calendar and changes how workflows through the firm, how responsibilities are allocated between accountant and client, and how capacity is managed during peak periods.
For many firms preparing for mandation, this represents the real adjustment: redesigning the work structure around quarterly deadlines.
The approval question firms are still working through
The end-of-year process became one of the most important areas of focus.
“The submission happens first, and then the final calculation is retrieved from HMRC,” Sai says. “That naturally leads to questions about how and when client approval should happen. We are seeing firms take different approaches, depending on how they manage risk and client relationships.”
For many firms, this represents a shift from traditional self-assessment workflows, where approval typically comes before submission.
“The key is having a clear and consistent approach to approval that works for the firm and the client.”
What matters most
By the later stages, the process had become more familiar.
“Once setup is complete and the workflow is understood, it becomes much more manageable,” Sai reflects. “What has become clear is that MTD works, but it requires firms to think differently about how work is organised.”
“The firms that became most comfortable were clear about how responsibilities were split between the firm and client, and how approval fits into their process. That is where the real adjustment sits.”
The right software handles the complexity of quarterly updates and year-end submissions. What firms control is the preparation. Firms have an opportunity now to onboard clients early, map approval workflows before deadlines hit, and identify bottlenecks while there is still time to adjust.
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Sai Charan Anaparthy is Senior Product Manager at Thomson Reuters, leading the Digita MTD for Income Tax delivery and development. He has worked closely with accountancy firms throughout the HMRC pilot, including the successful testing of both quarterly updates and end-of-year final declarations, giving him a practical, front-line view of how MTD is reshaping workflow across the profession. |
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