When is the deadline to file my income tax return?

If you are self-employed or business owner, you must file your income tax return - every year - before:

October 31 for the paper declaration.
January 31 for the online declaration.

After this period, you are liable to late payment penalties.

This also includes your foreign income.

You can also choose to use the services of an accounting firm to handle your declaration.

In England, the fiscal year begins on April 6 and ends on April 5 of the following year.

After January 31

If you have not yet declared your income by February 1, you are encouraged to file your declaration as soon as possible - in order to avoid significant penalties.

Penalties

If the January 31 deadline is passed, you will owe a first late penalty of £100.

This penalty applies to all latecomers, ultimately taxable or not.

You will also be exposed to:

A fine of £10 per day - up to a maximum amount of £900.
From 6 months late: a further fine of £300 or 5% of the tax due.
From one year late: a additional fine of £300.

You can contest a penalty only if you are unable to complete your declaration on time - for legitimate reasons (serious illness, bereavement, etc.).