The self-assessment tax return system in the United Kingdom requires taxpayers with specific financial circumstances to report their income and calculate their tax liabilities. Understanding the payment deadlines and the potential consequences of missing these deadlines is crucial for maintaining compliance with UK tax laws. This article will outline the key deadlines for self-assessment tax return submissions and payments and the penalties that apply if you miss these deadlines.

Deadlines for self-assessment tax returns and payments

If you are required to submit a self-assessment tax return, the deadlines for filing and payment are as follows:

Filing deadline:

Paper tax returns: If you choose to file a paper tax return, the deadline is midnight on 31 October, following the end of the tax year (5 April). For example, for the tax year 2022/2023, the paper tax return deadline is 31 October 2023.

Online tax returns: If you opt to file your tax return online, the deadline is midnight on 31 January, following the end of the tax year. For the tax year 2022/2023, the online tax return deadline is 31 January 2024.

Payment deadline: 

Regardless of your filing method, your payment deadline for any tax owed is midnight on 31 January, following the end of the tax year. For the tax year 2022/2023, the payment deadline is 31 January 2024.

Penalties for Missing Deadlines

If you miss the filing or payment deadlines for your self-assessment tax return, the following penalties may apply:

Late filing penalties:

• If you miss the filing deadline by one day, you will be charged an initial £100 fixed penalty.
• If your tax return is more than three months late, you will be charged an additional £10 per day penalty for up to 90 days, up to a maximum of £900.
• If your tax return is more than six months late, you will be charged an additional penalty of either £300 or 5% of the tax due, whichever is higher.
• If your tax return is more than 12 months late, you will be charged another penalty of either £300 or 5% of the tax due, whichever is higher.

Late payment penalties:

• If you miss the payment deadline by 30 days, you will be charged a penalty of 5% of the outstanding tax.
• If your payment is more than six months late, you will be charged an additional penalty of 5% of the tax outstanding at that time.
• If your payment is more than 12 months late, you will be charged another penalty of 5% of the tax outstanding at that time.

Conclusion

Adhering to the deadlines for self-assessment tax return submissions and payments is crucial for avoiding penalties and maintaining compliance with UK tax laws. Ensure you file your tax return and make any necessary payments by the appropriate deadlines to minimise the risk of incurring penalties. If you are unsure about your self-assessment obligations or need assistance with your tax return, consider seeking professional advice from a qualified accountant or tax adviser.