The introduction of Making Tax Digital for Income Tax Self Assessment (MTD ITSA)  from April 2026  marks one of the most significant overhauls to the UK tax system in recent years. Alongside digital record‑keeping and quarterly reporting, HMRC is introducing brand‑new penalty regimes  for both late filing and late payment. Penalty Dice And the new rules won’t only apply to digital filers. As confirmed in the 2025 Budget , these penalty regimes will extend to all self assessme