How and when do you pay Corporation Tax in the UK?

Full answer

**Corporation Tax (CT)** payment is separate from filing your Company Tax Return — the payment deadline and the CT600 filing deadline are different. **Payment deadline:** - **Standard companies:** 9 months and 1 day after the end of your accounting period - Example: accounting period ends 31 March 2027 → CT due by 1 January 2028 - **Large companies** (profits over £1.5 million): Quarterly Instalment Payments (QIPs) — payable in months 7, 10, 13 and 16 of the accounting period **CT600 filing deadline:** - Must be filed online within **12 months** of the accounting period end (3 months later than payment) **How to pay:** 1. Log in to **HMRC Business Tax Account** or pay via the HMRC website 2. Use your **10-digit Unique Taxpayer Reference (UTR)** as the payment reference 3. Payment methods: Faster Payments (same-day for amounts under £250,000), CHAPS (same-day for large amounts), BACS (3 working days) **Interest on late payment:** HMRC charges **late payment interest** at the Bank of England base rate + 2.5% (reviewed quarterly). As of 2026/27 this is approximately 7%. **Late filing penalties:** | Late period | Penalty | |---|---| | Up to 1 day late | £100 | | 3 months late | Further £100 | | 6 months late | 10% of unpaid tax | | 12 months late | Further 10% of unpaid tax | **Marginal relief calculation:** If profits fall between £50,000 and £250,000, calculate CT using the marginal relief formula: *Marginal Relief = (£250,000 − profits) × (profits ÷ augmented profits) × 3/200* This produces an effective marginal rate of **26.5%** through the tapering band.

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