As a self employed person, you will fall within the self assessment system with HMRC.
Self assessment is the process by which you advice HMRC of your income, gains and relevant expenses for a tax year. We can of course do this for you, by completing a tax return and sending this to HMRC and calculating your tax liability.
When talking about dates for tax, often the date is said to be 'during the tax year' or 'following the end of the tax year'. A tax year in the UK runs from the 6th April to the following 5th April.
31st January (during a tax year).
The first payment on accounts for the tax year, ending the following 5th April is due. For example, the first payment on account for the 2018/2019 tax year is due by the 31st January 2020.
April (Following the end of the tax year).
The tax year ends on the 5th April and shortly after this date, anyone who is required to file a return, will receive a notice advising that you must file a tax return for the tax year that has just ended.
31st July (Following the end of the tax year).
The second payment on accounts for the tax year ending the previous 5th April is due. For example, the second payment on account for the 2018/2019 tax year is due by the 31st July 2020.
The 5th October is the due date by which you need to notify HMRC that you have income that has not been taxed before you received it or capital gains in excess of £11,700 (2018/2019). This is so that HMRC can send you a notice a file a tax return. If you are self employed, you need to register with HMRC for tax purposes by this date.
If you file your tax return online, you will need to submit it by this date if you have employment or pension income and want HMRC to collect the self employed tax, through your PAYE tax code. This may be possible where you owe less than £3,000.00. If your income is more than £3,000.00, even more tax may be collected through your PAYE code.
All tax returns filed online must be submitted by this date. If you miss this deadline, a penalty will be charged even if you have no tax to pay or have already paid all of the tax owed to you.