Fines and Late Fees on Self Assessment Tax Returns: Understanding the Consequences

Published: 24/01/2024 By Hannah Duncan

For anyone who may be considering filing or paying their Self Assessment tax return late, here is a reminder of the potential penalties and interest charges.

Submitting your Self Assessment tax return late
If you submit your Self Assessment (SA) tax return after midnight on 31st January you will be charged a fixed rate penalty of £100. Even if no tax is due or the tax owed has been paid, the £100 will still apply.

Following the initial fine, a further £10 per day penalty will be charged for up to 90 days whilst the SA tax return remains unfiled (max charge of £900).

If after 6 months, the SA tax return has yet to be submitted, a further 5% of the tax due or £300, if higher will be charged.

A further 5% penalty or £300 applies again if after 12 months the SA tax return has still not been submitted but, HRMC will also take behaviour into account i.e. if the tax payer is deliberately withholding information further fines could be applied.

Paying your Self Assessment tax bill late
In addition to this, if the tax owed is paid late the following charges apply:

30 days late - 5% of tax due
6 months late - 5% of tax due
12 months late - 5% of tax due dependant on behaviour

HMRC interest charges
Not forgetting on top of all these penalties HMRC charge an annual interest rate of 7.75% on all outstanding tax balances, from the due date until the date of the payment. Meaning you will be charged interest on any unpaid tax as well as face the above mentioned penalties.

HMRC offer a penalty calculator which you can access here

If you are struggling to make your tax payment, get in touch with HMRC with a view to making a time to pay arrangement.