MTD Income Tax is now a live planning issue for accountancy practices onboarding MTD Income Tax clients. A rushed onboarding creates recurring quarterly problems, so practices need a standard checklist before the first update. This guide narrows the job to client onboarding for MTD, so the business can move from annual clean-up to a repeatable quarterly review.

For wider context, use Making Tax Digital and Software . If the topic affects a filing deadline, software choice or tax treatment, confirm the live position before acting. The workflow below is designed to keep the evidence in one place so the owner, bookkeeper and accountant can all review the same record.

Official point to verify

GOV.UK says people required to use MTD for Income Tax from 6 April 2026 should sign up, must be registered for Self Assessment and must have submitted a tax return in the last two years. Check the current wording in GOV.UK MTD Income Tax sign up guidance before making a binding filing, software or tax decision.

What to control

AreaControlWhy it matters
ScopeIdentify every active trade and property sourceThe software setup follows the source list
AuthorityConfirm agent services and software accessThe practice cannot review what it cannot see
RecordsMove opening records into the agreed toolClient spreadsheets need a controlled handover
TimetableSet reminders and query cut-offsQuarterly work needs predictable dates

Review routine

Build the routine around monthly bookkeeping rather than waiting for the quarterly deadline. Reconcile the bank, clear uncategorised transactions, review owner drawings or property transfers, then let the software produce the update totals. The accountant should review exceptions, not rebuild the ledger.

A useful review note should answer three questions: what source evidence was used, what judgement was applied, and who approved the treatment. Keep that note beside the transaction or period report rather than in a separate inbox.

Common mistakes

  • Accepting a client spreadsheet without mapping categories
  • Assuming old Self Assessment habits fit quarterly updates
  • Not defining who presses submit

The best prevention is a short, repeated checklist. If a control is too complicated to run every month or quarter, it will probably fail when the deadline is close.

How ReAI helps

ReAI helps by keeping invoices, bank imports, receipts, review notes and accountant access in one place. That makes quarterly MTD work a by-product of ordinary bookkeeping instead of a separate spreadsheet exercise. For hands-on help with setup, see Accounting Assistance for Small Businesses .

Summary

Treat MTD Income Tax client onboarding as a recurring accounting control, not a one-off admin task. Put the source data, review owner, exception list and submission evidence in the same system before the deadline arrives. That makes compliance work easier to check and much less dependent on memory.