Free Tool · Updated March 2026
HMRC Late Filing Penalty Calculator
Enter how late your Self Assessment return is and your estimated tax bill. We calculate your exact penalty charges plus HMRC interest — updated for 2025/26 rates.
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90 days
1 day90 days (daily fines start)2 years
£5,000
£0 (nil return)£50,000£100,000
Not sure? Use your best estimate — you can amend the return later. Penalties still apply on nil returns.
Daily charges are running. The 6-month surcharge adds £300 in 93 days.
Assumptions: Self Assessment (individual). HMRC interest rate 7.5% p.a. (Bank of England base rate 5.0% + 2.5%), current as at March 2026. Penalty figures based on published HMRC schedule. Results are indicative — actual figures depend on your specific filing history.
Total estimated exposure
£192
Penalties (£100) + interest (£92)
Full breakdown
Initial £100 fixed penalty£100
HMRC interest on unpaid tax (7.5% p.a.)£92
Total penalties
£100
Interest on tax
£92
Tax owed
£5,000
Grand total
£5,192
What filing TODAY saves vs. waiting
vs. waiting to 3 monthsSave £10
vs. waiting to 6 monthsSave £1,200
vs. waiting to 12 monthsSave £1,500