Free Tool · Limited Companies
Corporation Tax Late Filing Penalty Calculator
A late limited company return means fines from two places at once: HMRC for the CT600 and Companies House for the annual accounts. This calculator shows both — plus your strike-off risk.
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Your company's situation
60 days
1 day6 months (10% charge)2 years
£10,000
£0£100,000£200,000
Was the previous year's return also late?
If your company was late in the prior year, HMRC doubles the flat-rate penalties and Companies House also doubles its fines.
CT600 deadline is 12 months after the accounting period end. Companies House deadline for private companies is 9 months after period end — this calculator reflects the typical gap between the two. Interest rate 7.5% p.a. (March 2026).
Total estimated exposure
£973
Across HMRC + Companies House + interest
HMRC penalties
£100
CT600 late filing
Companies House
£750
Late annual accounts
Full breakdown
HMRC flat penalty£100
Companies House fine£750
HMRC interest on unpaid corporation tax (7.5% p.a.)£123
CT owed to HMRC
£10,000
All penalties + interest
£973
Total including CT owed
£10,973