Harnett Accontants

Harnett & Co | Chartered Accountants, Kingston upon Thames
Global House Business Centre 1 Ashley Avenue Epsom Surrey KT18 5AD
ICAEW Authorised Practice
Tax Insights

What Are The Highest Penalties For Late Tax Returns?

As Accountants in Richmond we are often asked this question, ‘what are the highest penalties for late tax returns’.

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Reviewed for 2026/27: All tax figures and HMRC rules in this article reflect current guidance for the 2026/27 tax year.

Key Considerations

All self-assessment Tax returns must be submitted to HMRC in paper format by the end of January each year. In prior years you would receive a penalty of £100 if presented after this date; however, since 2011 this has slightly changed with additional penalties receivable with the initial £100 penalty. These are, if you are anything more than three months late submitting a daily basis of £10 per day will be given up to the maximum of £900. If your self-assessment Tax is over six months late you will receive a penalty calculated as the higher of £300 and 5% of the tax already due. This will continue every six months that passes.

It is important to remember that when referring to late partnership tax return, these penalties will apply to each partner in the partnership.

Additionally if you’re late paying the correct amount of your self-assessment Tax a further penalty will be given. This penalty is calculated as 5% of the outstanding tax due at the following intervals: 30 days late, 6 months late and 12 months late.

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📌 Important: Tax rules change regularly. Always verify current figures at gov.uk/hmrc or speak to a qualified accountant.
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