Self Assessment late filing and late payment penalties
Checked 18 July 2026 · How we check our figures
What it is
Self Assessment carries two separate duties with two separate penalty ladders: the return and the payment, each with its own clock, under Sch 55 and Sch 56 FA 2009. The brown envelope that starts most journeys here is a late tax return fine of 100 pounds. What the envelope does not say is that the 100 pounds arrives even where no tax is owed, that the filing ladder keeps climbing on its own, and that paying the bill does not stop it, any more than filing stops the payment ladder (gov.uk, checked 2026-07-18).
Reading the notice
The filing ladder: 100 pounds the day after the deadline; from 3 months late, 10 pounds a day for up to 90 days, a further 900 at most; at 6 months and again at 12, the greater of 300 pounds or 5 per cent of the tax due (gov.uk, checked 2026-07-18).
The payment ladder: 5 per cent of the unpaid tax at 30 days, at 6 months and at 12 months, with daily interest running underneath from day one, the hmrc interest guide's territory (gov.uk, checked 2026-07-18).
A partnership return that is late fines every partner: each receives the penalties, not the firm alone (gov.uk).
The decision in front of you
File now even if the bill cannot be paid: the filing ladder is the faster climber, it stops on the day the return arrives, and the payment side can then be managed on its own.
Ask for Time to Pay before the 30 day mark: an arrangement made and kept holds the 5 per cent payment steps off, while interest continues on the balance (gov.uk).
Appeal with a reasonable excuse within 30 days of the penalty notice: the excuse must hold at the missed deadline, and the return must follow promptly once it has passed (gov.uk).
Do nothing and both ladders climb together: a year of silence on a return with no tax owed still reaches 1,600 pounds, 100 plus 900 plus 300 plus 300, before any payment penalties even exist (arithmetic from the gov.uk steps, checked 2026-07-18).
What happens next
The 5 per cent payment steps are aimed at the unpaid balancing payment; the two payments on account gather interest when late but sit outside these steps (s. 59B TMA 1970; Sch 56 FA 2009).
A penalty notice has its own clock: the penalty is payable within 30 days of the date on it (gov.uk).
A points-based regime is rolling in with Making Tax Digital from April 2026 and is set to reach the wider Self Assessment world after it: this guide describes the classic ladder, and the calculator at /fines/self-assessment-penalties carries the boundary in its limits box.
The numbers
Filing: 100 pounds fixed; 10 pounds a day from 3 months, capped at 900; the greater of 300 pounds or 5 per cent at 6 and again at 12 months (gov.uk, checked 2026-07-18).
Payment: 5 per cent of the unpaid tax at 30 days, 6 months and 12 months (gov.uk, checked 2026-07-18).
The full run for any lateness, with both ladders and interest: the calculator at /fines/self-assessment-penalties.
The deadlines
31 January is both clocks' midnight for the online return and the balancing payment (gov.uk).
The filing ladder steps at 3, 6 and 12 months; the payment ladder at 30 days, 6 and 12 months (gov.uk).
30 days from the penalty notice to pay it or to appeal with a reasonable excuse (gov.uk).
What people get wrong
Assuming no tax means no penalty: the filing ladder hangs on the return, not the bill, and the 100 pounds arrives for a nil year too (gov.uk).
Waiting to file until the money is there: the two ladders are independent, and the filing one climbs faster than the payment one.
Registering late and relaxing: a registration after 5 October with tax still unpaid at 31 January can bring a separate failure to notify penalty on top (gov.uk).
Authority
Sch 55 and Sch 56 FA 2009; s. 59B TMA 1970; gov.uk, Self Assessment penalties