07/08/2025 – VAT return submission (online): month or quarter-end 30 June 2025
Just as a double check 7 August 2025 is the last day to submit your VAT return online for any VAT period that ended on 30 June 2025, whether you file monthly or quarterly.
HMRC’s Making Tax Digital rules mean all submissions must be done digitally. Missing this date risks late filing penalties and could flag your account for surcharges or interest.
Double-check: Make sure you’ve both filed the return and paid any VAT owed by this date to stay fully compliant.
Useful link: Submit VAT returns – GOV.UK
19/08/2025 – PAYE, NIC and CIS payment (postal): month-end 5 August 2025
If you pay your PAYE, National Insurance Contributions (NIC), or Construction Industry Scheme (CIS) deductions by post, your payment for the tax month ending 5 August 2025 must reach HMRC by 19 August 2025.
This applies if you pay by cheque through the post – HMRC must receive cleared funds by this date to avoid late payment interest or penalties.
Tip: Consider paying electronically where possible — the deadline for electronic payments is slightly later (typically 22nd of the month). Always allow extra days for postal delivery delays.
Useful link: Pay PAYE and CIS – GOV.UK
19/08/2025 – CIS return: payments made to subcontractors in the month to 5 August 2025
If you operate under the Construction Industry Scheme (CIS), you must submit your monthly CIS return to HMRC by 19 August 2025 for any payments made to subcontractors in the tax month ending 5 August 2025.
This return shows how much you paid your subcontractors and how much CIS tax you deducted. Even if you didn’t make any payments that month, you must file a nil return to stay compliant and avoid a penalty.
Tip: File your CIS return online using HMRC’s CIS online service or through compatible payroll software. Late returns can result in automatic penalties starting at £100.
Useful link: Submit CIS returns – GOV.UK
22/08/2025 – PAYE, NIC and CIS payment (electronic): month-end 5 August 2025
If you pay your PAYE, National Insurance Contributions (NIC) and Construction Industry Scheme (CIS) deductions electronically, your payment for the tax month ending 5 August 2025 must clear HMRC’s account by 22 August 2025.
Electronic payment is the preferred method for most employers because it gives you a few extra days compared to posting a cheque — and it’s more secure.
Tip: Make sure your payment reaches HMRC’s bank by the deadline. Factor in your bank’s cut-off times, weekends, and bank holidays that might delay the transfer.
Useful link: Pay PAYE and CIS – GOV.UK
31/08/2025 – Corporation Tax returns: 31 August 2024 year ends
If your company’s accounting year ended on 31 August 2024, you must file your Company Tax Return (CT600) with HMRC by 31 August 2025.
Unlike the Corporation Tax payment, which is due 9 months and 1 day after your year-end, the return itself must be filed within 12 months. Missing this deadline can lead to automatic late filing penalties, starting at £100 and increasing if you miss further deadlines.
Tip: Submit your return online through HMRC’s Company Tax Return portal or use approved accounting software. Keep copies of your final accounts and computations in case HMRC requests further information.
Useful link: File your Company Tax Return – GOV.UK
31/08/2025 – VAT partial exemption: annual adjustment due this quarter for 31 May stagger
If your business is partially exempt for VAT meaning you incur both taxable and exempt sales you must perform an annual adjustment to ensure you’ve reclaimed the correct amount of input VAT over the year.
For businesses on a 31 May VAT stagger (year end 31 May 2025), your annual partial exemption adjustment must be included in the first return after your annual adjustment date. This means the adjustment is due in your VAT return for the period ending in August 2025, with submission and payment by the standard deadlines.
Tip: Partial exemption can be complex. Double-check your de minimis limits, calculation methods, and ensure you have the evidence to support your input VAT claims.
Useful link: VAT Partial Exemption – GOV.UK
In conclusion staying on top of your August accounting deadlines
Managing multiple tax and accounting deadlines can be stressful — especially if you’re juggling payroll, VAT, and your day-to-day business. At Accounting Wise, we help UK businesses and sole traders stay compliant, meet deadlines, and avoid costly late penalties. If you’d like help staying on track, get in touch with our team today.
