Tax Diary: May to June 2023 Deadlines That May Still Matter

This tax diary covers key tax deadlines that fell between May and June 2023 and is relevant for taxpayers who want to check whether any obligations from that period were missed.

Although these dates have passed, unresolved filing or payment issues linked to them can still result in penalties, interest, or HMRC follow-up action, issues that are often only identified later when matters are reviewed with a tax consultant in London.

Key Tax and Payroll Deadlines for May and June 2023

• 1 May 2023 – Due date for corporation tax due for the year ended 30 July 2022.
• 19 May 2023 – PAYE and NIC deductions due for month ended 5 May 2023. (If you pay your tax electronically the due date is 22 May 2023).
• 19 May 2023 – Filing deadline for the CIS300 monthly return for the month ended 5 May 2023.
• 19 May 2023 – CIS tax deducted for the month ended 5 May 2023 is payable by today.
• 31 May 2023 – Ensure all employees have been given their P60s for the 2022/23 tax year.
• 1 June 2023 – Due date for corporation tax due for the year ended 31 August 2022.
• 19 June 2023 – PAYE and NIC deductions due for month ended 5 June 2023. (If you pay your tax electronically the due date is 22 June 2023).
• 19 June 2023 – Filing deadline for the CIS300 monthly return for the month ended 5 June 2023.
• 19 June 2023 – CIS tax deducted for the month ended 5 June 2023 is payable by today.

Why Past Tax Diary Deadlines Are Still Relevant

Tax deadlines do not become irrelevant simply because time has passed. Where a return was not submitted or a payment was made late, the matter can remain open until it is resolved.

This means May and June 2023 deadlines may still affect you today if HMRC considers an obligation outstanding, even where no issue was originally flagged by a tax specialist in London at the time.

Common Obligations Around May and June

Deadlines during this period often relate to:

• Self Assessment filing and payment obligations
• VAT return submissions and payments
• PAYE and National Insurance reporting and payments

Which obligations applied will depend on your circumstances, such as whether you were self-employed, an employer, or VAT-registered.

What Happens If a Deadline Was Missed?

If a tax deadline from May or June 2023 was missed, HMRC may have issued penalties or charged interest.

In some cases, penalties increase over time until the return is filed or the payment is made. Even where no immediate penalty was raised, HMRC may still pursue the issue later.

Why It Is Worth Reviewing Now

Some taxpayers assume older deadlines no longer matter. In practice, unresolved issues often resurface through HMRC reminders, statements of account, or compliance checks.

Reviewing whether all obligations from May to June 2023 were met can help avoid unexpected demands or enforcement action.

HMRC Guidance on Late Tax Deadlines

HMRC provides guidance on late filing, late payment, and the penalties and interest that may apply on
GOV.UK.

Did You Miss Any May or June 2023 Deadlines?

Whether any action is required now will depend on which obligations applied to you at the time and whether they were dealt with correctly. For individuals and businesses in Kingston upon Thames and nearby areas such as Surbiton and Hampton Wick, CIGMA Accounting can review your position and confirm whether anything remains outstanding or needs to be corrected.