If your company’s accounting period ended on 31st October 2024, your Corporation Tax return (CT600) must be filed with HMRC by 31st October 2025.

This filing includes:

• Completing and submitting the CT600 form through HMRC’s online service or approved software.

• Providing detailed accounts, profit and loss calculations, and any claimable reliefs or allowances.

• Ensuring that your figures align with your statutory accounts filed at Companies House.

⚠️ Penalties for late filing:

• 1 day late: £100

• 3 months late: another £100

• 6 months late: HMRC will estimate your Corporation Tax bill and add a 10% penalty.

• 12 months late: another 10% of the unpaid tax.

💡 Tip: Your Corporation Tax payment deadline is different from your filing deadline (payment is usually due 9 months and 1 day after year-end). Even if you’ve already paid your tax, you still need to file the return on time to avoid penalties.

Submitting early not only avoids stress but also gives you more time to plan effectively for the year ahead.