Tag: Penalties
Self Assessment deadlines and late-filing penalties: what do I owe if I miss 31 January?
The online return and the payment are both due by 31 January after the tax year ends. File late and you owe £100 on day one, £10 a day once you pass three months, and further penalties at six and twelve months. A return filed a year late costs at least £1,600 even if you owe no tax at all. Pay late and HMRC adds 5% of the unpaid tax at 30 days, 6 months and 12 months, plus interest. Cited to GOV.UK, checked 20 October 2026.