Late filing penalty calculator

Two separate clocks run against a company: Companies House fines late accounts automatically, and HMRC fines a late Corporation Tax return on top. Here's what lateness actually costs.

How many months late?The accounts were ALSO late last year (Companies House doubles the penalty)The return's filing deadline was BEFORE 1 April 2026 (the older £100 flat penalties apply)This is the THIRD late Corporation Tax return in a row (flat penalties rise to £1,000 each)

Companies House — late accounts

—

Automatic, no appeals for forgetting. Bands: £150 (<1 month), £375 (1–3), £750 (3–6), £1,500 (over 6) — doubled when late two years running.

HMRC — late Corporation Tax return

—

£200 immediately, another £200 at 3 months, then 10% of the unpaid tax at 6 months and again at 12 (for deadlines from 1 April 2026 — older deadlines used £100 flat penalties). Three late returns in a row and the flat penalties rise to £1,000 each. Rules checked 30 August 2026 against GOV.UK.

The cheapest penalty is the one that never happens — GoTaxes tracks every deadline and reminds you at 30 and 7 days. Prepare free →