Client - MTD Tax Return

Reviewing a client's Making Tax Digital Income Tax year and sending their tax return to HMRC. The review is thirty or more HMRC requests behind one call — every income source's obligations, reporting setup, held position and year-end work, all their other income, losses, liability adjustments, HMRC's calculation, and the declaration with whatever is standing in the way — so it is slow the first time a year is opened and fast afterwards. What it reports as standing in the way is advice rather than a gate: HMRC hold the real rules and a practice that disagrees may proceed. The one exception is the declaration, which HMRC require the software itself to enforce. Behind its own permission, separate from quarterly updates, because HMRC allow a supporting agent to file the second and not the first. This filing is not idempotent: a submission whose outcome is unknown is settled by reconciling it against HMRC's own record, never by sending again.