Quick answer: A solid MTD onboarding checklist covers four stages: confirming eligibility and mandation date, choosing and setting up software, migrating historical records and connecting bank feeds, and a supervised first quarterly submission before handing ongoing responsibility to the client (or your practice, if you’re managing it for them).
The practices with the smoothest MTD rollouts tend to have a repeatable onboarding process rather than treating each client as a one-off project. Here’s a checklist structure worth adapting to your practice.
Stage 1: Confirm eligibility and timing
- Calculate the client’s qualifying income from their most recent relevant Self Assessment return.
- Confirm their mandation date (April 2026, 2027, or 2028) based on that figure, using our qualifying income explainer as a reference.
- Check for any applicable exemptions, digitally excluded status, foster carer status, or non-resident easements, before assuming standard mandation applies.
Stage 2: Choose and set up software
- Match software to the client’s complexity, single sole trade, multiple properties, mixed income sources all warrant different levels of feature depth. See our software choice checklist.
- Set up agent access so your practice can review and, where agreed, submit on the client’s behalf.
- Agree who is responsible for what, client self-service, practice-managed, or a hybrid, and document it clearly for both sides.
Stage 3: Migrate records and connect bank feeds
- Connect all relevant bank accounts via open banking, not just the primary one; a missed account is one of the most common causes of incomplete quarterly updates.
- Import or reconstruct records for the portion of the current tax year already elapsed before onboarding, so quarterly figures are complete from day one.
- Review early automated categorisation carefully with the client before relying on it unsupervised.
Stage 4: Supervise the first submission
Walk the client through their first quarterly update directly rather than handing over instructions and hoping for the best. This is also the point to set calendar reminders, for both the client and your practice, well ahead of each subsequent deadline. See quarterly updates to HMRC: a walkthrough for the mechanics you can walk through together.
Managing MTD across a growing client list? See the CleanBooks AI Partner Programme.
