Corporation Tax return filing
All limited companies are subject to Corporation Tax, and being aware of the deadlines is key to navigating the financial year without penalties. While VAT and Self Assessment tie the filing and payment deadlines together, Corporation Tax has two separate dates to remember. Here, we outline how the dual deadlines work to help you avoid getting caught out.
The payment deadline
Counterintuitively, the Corporation Tax payment deadline comes before the filing deadline, which catches many businesses out. For the majority of small and medium-sized enterprises (SMEs), Corporation Tax must be paid 9 months and 1 day after the end of their accounting period.
If a company’s year-end is 31 March, their Corporation Tax payment is due by 1 January the following year. The deadline applies whether or not you have prepared and filed your tax return. HMRC expects payments based on your liability, which means that if the figure has not yet been calculated, an accurate estimate should be paid and then reconciled later.
Companies whose taxable profits exceed £1.5 million are required to pay Corporation Tax in quarterly installments, two of which will fall before year end.
The filing deadline
The filing deadline for the Corporation Tax return (CT600) is 12 months after the end of the accounting period. A year end of 31 March 2025 requires the CT600 to be filed by 31 March 2026. Note that by this point the payment must already have been made.
Penalties for missing the Corporation Tax deadlines
As with VAT and Self Assessment, HMRC applies an automatic penalty – in this case £100 – for filing the CT600 late. If the return is filed more than three months late, an additional £100 is charged.
If the deadline is missed by six months or over, HMRC makes its own estimate of the tax bill (called a ‘determination’) and charges an additional 10% of any unpaid tax. A further 10% penalty is incurred if the return is filed 12 months late.
In the event that a company files its Corporation Tax return late three times in a row, the initial penalties increase from £100 to £500 each.
There is no fixed fine for late payment of Corporation Tax, but interest is charged from the day after the payment was due. If payment is due on 1 January, for example, interest begins to be charged from 2 January.
How to pay Corporation Tax
HMRC accepts Corporation Tax payments by bank transfer, BACS, Direct Debit or online via a business debit or corporate credit card. If paying by BACS, be sure to allow a minimum of three working days for the payment to clear.
Leave clock watching to the professionals
If you are busy trying to grow your organisation and have multiple balls to keep in the air, why not let a professional handle your Corporation Tax filing and payment? A dedicated accountant can ensure your returns are filed accurately and on time, and that you don’t face penalties and other measures.
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