Making Tax Digital for Income Tax — what are the actual quarterly update deadlines and what happens if I miss one?

Hi Hazel, here's the practical picture. Under MTD for Income Tax, your tax year is split into four quarters: 6 April to 5 July, 6 July to 5 October, 6 October to 5 January, and 6 January to 5 April — and each quarter's update must reach HMRC by the 7th of the following month, so 7 August, 7 November, 7 February and 7 May. On top of that, you still file a final declaration (the EOPS) by 31 January after the tax year, which is where you confirm the figures and claim allowances. Missing an update won't hit you with an instant fine: HMRC runs a points-based penalty system, so a late update earns you a penalty point and only repeated lateness within a set window turns into a financial penalty — but do stay on top of them, because points accumulate. MTD for Income Tax started from April 2026 for self-employed people and landlords with qualifying income over £50,000, so check whether your income puts you in scope. You'll need MTD-compatible software to keep digital records and submit the updates, and my advice is to get set up on software well before your first deadline — it's much calmer than rushing in May.