When does the new tax year begin and end in the UK?

The tax year begins on 6 April and ends on 5 April of the following year. Changes to new tax rules are often introduced at the beginning of the new tax year.

For example, 6 April 2023 is the first day of the 2023/24 tax year with the last day being 5 April 2024.

What is self-assessment?

Self-Assessment is a system HM Revenue and Customs (HMRC) uses to collect Income Tax.

Tax is usually deducted automatically from wages and pensions. People and businesses with other income (including COVID-19 grants and support payments) must report it in a tax return.

Who should file self-assessment?

If you are self-employed as a sole trader and earned more than £1,000, that means you don’t have an employer to deduct PAYE and NI from your monthly gross income. Instead, you must submit a Self- Assessment tax return to HMRC. This tells them how much you have earned, so they can calculate the tax you owe.

Self-Assessment is for sole traders, an individual with other income from dividends from a limited company and or capital gains, earning taxable income of more than (£100,000) or investment income, you had to pay the high-income child benefit charge or if you’re a partner in a business partnership.

You may also need to send a tax return if you have any untaxed income, such as:

  • some COVID-19 grant or support payments
  • tips and commission
  • income from savings
  • foreign income

When are you required to send a self-assessment tax return?

31 January – Self Assessment tax return filing deadline for online tax returns for the year ended 5 April.

31 January – You must pay the income tax you owe by this deadline.

5 October – You must inform HMRC by 5 October following the tax year in which you started trading If you need to submit a Self-Assessment tax return for the first time,

Midnight 31st October- If you’re doing a paper tax return, you must submit it by this deadline for the year ending 5th April.

A penalty is charged if you fail to send a tax return and miss the deadline for submitting
it or paying your bill. Late filing attracts a penalty of £100 if your tax is up to 3 months late and
you’ll have to pay more if it’s later, or if you pay your tax bill late and interest on late payments

You will need to maintain your bank account statements and receipts.

You can change your self-assessment returns within 12 months of the Self-Assessment deadline, online
or by sending another paper return. You must wait 3 days (72 hours) after filing before updating your
return for online returns. For paper tax returns you will call HMRC and request form SA100.

A company’s annual accounts also called ‘statutory accounts’ – are prepared from the company’s
accounting records at the end of your company’s financial year. This account is sent to Companies
House and HM Revenue and Customs (HMRC) as part of your Company Tax Return.

You can file with Companies House and HMRC together or separately. When you set up your limited
company, you automatically get different reporting dates for the first:

  • Annual accounts you send to Companies House
  • Company Tax Return you send to HM Revenue and Customs (HMRC)

You may also have to send (‘file’) 2 tax returns to cover your first year in business.

After the end of its financial year, your private limited company must prepare:

  • Full (‘statutory’) annual accounts
  • A Company Tax Return

You need your accounts and tax return to meet deadlines for filing with Companies House and HM
Revenue and Customs (HMRC) as follows:

21 months after the date you registered with Companies House for first account filling with companies

9 months after your company’s financial year ends for filling annual accounts with Companies House.

12 months after your accounting period for Corporation Tax ends to file Company Tax Return.

9 months and 1 day after your ‘accounting period’ for Corporation Tax ends to pay Corporation Tax or
tell HMRC that your limited company does not owe any.

If you don’t file your Company Tax Return by the deadline, you will have to pay penalties. If your return is
late by a day, the penalty is £100, plus a further £100 if the return is more than three months late. Where
the tax return is six months late, HMRC will write informing you how much Corporation Tax they think you
must pay. This is called a ‘tax determination’, which can’t be appealed against.

You should be sending accounts to Companies House each year while your company was dormant – so
your reporting dates stay the same for annual returns and accounts. Your Corporation Tax accounting
period is different. It begins when your company restarts business activities.