When is the Self Assessment deadline for your self-employment workforce?

30/11/2023Zara James

The self-employed subcontractors you engage with will need to submit a Self Assessment Tax Return for tax year 2022/23 by 31st January 2024

What is a Self Assessment Tax Return?

A Self Assessment Tax Return is a system that HMRC uses to collect Income Tax. It shows how much an individual has earned, and from what sources, over the duration of a tax year. 


If any of the following applied in the last tax year (6th April to 5th April), then you must complete a Self Assessment Tax Return:


  • You were self-employed as a sole trader and earned more than £1,000 (after claiming tax relief)
  • You were a partner in a business partnership
  • You had a total taxable income of more than £100,000
  • You had to pay the High Income Child Benefit Charge


Also untaxed income, such as the following, may mean you have to complete a tax return:


  • Some COVID-19 grant or support payments
  • Money from renting out a property
  • Tips and commission
  • Income from savings, investments and dividends
  • Foreign income


There are also other important dates throughout the tax year to be aware of, which we have summarised below. 

What are the Important Dates for the Self Assessment Tax Year?

6th April 2023: Start of the 2023/24 tax year

The UK tax year runs from the 6th April to the 5th April of the following year. 

Any income earned within these dates must be reported in a Self Assessment Tax Return for the corresponding year. The current Self Assessment Tax Return is reporting on income earned between 6th April 2022 and 5th April 2023.

5th October 2023: Deadline for telling HMRC you need to complete a return for 2022/23 tax year


If you are newly self-employed or have never submitted a Self Assessment Tax Return, you have to register with HMRC. Following this, HMRC will provide you with a Unique Tax Reference (UTR) number. Once this is done, you do not have to register with HMRC again. 


The deadline to register with HMRC for a Self Assessment Tax Return was 5th October 2023. 


If you have missed this deadline, it’s important to inform HMRC as soon as possible in order to limit any penalties you may face.


31st October 2023: Deadline for paper Self Assessment Tax Return forms

The deadline to submit a paper Self Assessment Tax Return for tax year 2022/23 to HMRC was the 31st October 2023. 

However, if you missed this date, the deadline for online Self Assessment Returns is the 31st January 2024, and it is a quicker and simpler process. 

30th December 2023: Deadline to opt into paying tax via PAYE

You may be eligible to pay your tax via PAYE if the following applies:

  • Your tax bill is less than £3,000
  • You already pay tax through PAYE (as an employee or if you get a company pension) 
  • You file your online tax return by 30th December

Paying through PAYE means your tax bill will be taken from your salary (or pension) in monthly instalments along with your usual tax deductions, instead of a lump sum on 31st January. 

You must file your Self Assessment Tax Return by 30th December to opt into paying tax via PAYE. 


31st January 2024: Deadline for online Tax Returns and tax bill payment deadline

Online Self Assessment Tax Returns for the 2022/23 tax year must be completed by midnight on 31st January 2024 or you will face a late filing penalty.

The payment deadline for any tax owed is also midnight on 31st January 2024. This includes tax owed for the previous tax year (also known as the balancing payment) and your first payment (advance payments towards your tax bill) on your account. There will also be penalties incurred for late payments.


There are two payments to be made every year, on 31st January and 31st July, unless:


  • Your Self Assessment tax bill is less than £1,000
  • More than 80% of the previous year’s tax owed has been paid (for example, via tax code or your bank has already deducted interest on savings)


5th April 2024: End of the 2023/24 tax year 


On 5th April 2024, your tax allowances will reset and HMRC will send a notification to file your next tax return for the 2023/24 tax year. 


6th April 2024: Start of the 2024/25 tax year


The new 2024/25 tax year begins on 6th April 2024. 

31st July 2024: Second tax bill payment deadline


The payment deadline for the second instalment tax payment (or ‘payment on account’) is midnight on 31st July 2024. 

It’s important to keep up with tax obligations and provide information and payments to HMRC by the required deadlines. Missing a deadline can result in late filing penalties and interest charged on late payments. You can read more about this on our blog here.

How can Indigo help?

Every subcontractor’s statement of earnings is held by Indigo and uploaded to their individual, safe and secure, Indigo portal. This means subcontractors can obtain this information directly from us ready to complete their tax returns. 


This saves contractors admin time, fuss and money.


Please get in touch for a free Business Compliance Health Check if this is something you think Indigo can help you with. Or learn more about how our solutions can help here.


If you are a subcontractor needing statements for your Self-Assessment Tax Return, please check your Indigo portal or get in touch with one of our support team.


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