Tax calculator

Self Assessment Penalty Timeline

Check a narrow legacy-regime filing and payment penalty timeline with uncertain cases routed to HMRC.

  • Tax year shown with the calculator
  • Assumptions explained
  • Source-linked methodology

Legacy personal online returns · 2010/11 to 2025/26, with exclusions

Check a late-filing and late-payment penalty timeline

The tax year sets the normal 31 January online deadline. Filing and payment penalties use separate statutory amounts, and late-payment interest is not included.

Enter the return year, for example 2023/24. This checker derives the normal online deadline and routes COVID-easement and new-regime years to HMRC.

Is this one straightforward personal online return?

Choose yes only for an individual return with the normal online deadline, no reasonable-excuse claim or appeal, no deliberate withholding, partnership/trust/estate, amendment, altered notice deadline, Time to Pay, part payments, credits or earlier-year allocation.

Enter the date HMRC received the completed online return.

Schedule 55 uses the tax liability that would have been shown in the return for the 6- and 12-month filing comparisons.

Schedule 56 uses the amount unpaid at each trigger. Include the relevant balancing payment and any unpaid payments on account, after credits and payments. Use this only where that entire balance was cleared in one payment.

Enter the effective date the full balance above reached HMRC. Part payments are outside scope.

Optional

Leave blank if no daily-penalty notice applies. If the return reached the statutory three-month point, no daily amount or total is calculated without the actual notice start date.

Your dates and tax figures are used only for this server-rendered estimate and are not added to a lead record.

Scope and important exclusions

This checker derives only normal online deadlines from 2010/11 to 2025/26. It routes 2018/19, 2019/20 and 2020/21 because COVID easements affected penalties, and routes later years because the penalty regime changes.

It excludes interest, reasonable excuse, appeals, deliberate withholding, altered deadlines, partnerships, trusts, estates, Time to Pay, amendments, determinations, part payments, credits and payment allocation.

How to understand your result

The calculator content must explain the result breakdown, applicable period, rounding, assumptions, exclusions and the primary sources used by its versioned tax table.