Self Assessment (SA100)

What is the SA100?

The SA100 is the main Self Assessment tax return form used by an individual to report their income, allowances, and tax reliefs. If an individual is required to complete any additional Self Assessment forms, those forms must also be submitted alongside the SA100.

Why it is necessary to submit SA100?

It is necessary to submit the SA100 because it contains an individual’s personal information, such as full name, date of birth, address, telephone number, and National Insurance number. The form is also used to indicate the types of income that the individual reports on other supplementary forms, such as the SA101, SA102, SA103, and others.

What kind of information covered int it?

The SA100 covers information on an individual’s income, such as dividends, interest from UK banks or building societies, pensions, and annuities.

Key dates to know

• April 6 – New tax year starts.
• October 5 – Deadline to register for Self Assessment (if it’s your first time).
• October 31 – Paper filing deadline (rare these days).
• January 31 – Online filing deadline and final tax payment.