Short answer
Nine months and one day after the end of your accounting period. For a 31 March year end, tax is due by 1 January. Large companies with profits over £1.5m pay quarterly instalments instead.
Corporation tax
When is my corporation tax payment due?
Corporation tax is payable nine months and one day after the end of the accounting period, before the CT600 deadline.
Written and reviewed by Waqas Sagar Member of ICAEW, Fellow of ACCA, Fellow of AAT, a double graduate and entrepreneur at heart, helping startups grow and serving thousands of businesses nationwide with an excellent team. Published by LimitedCompany.Accountants, 12 London Road, Morden, London SM4 5BQ. Reviewed 12 September 2026 against 2026/27 UK rates and current Companies House and HMRC guidance.
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QuickBooks PartnerCertified ProAdvisor100+ yearsCombined team experienceFully insuredUp to £2m indemnityWhat this means for your company
Nine months and one day after the end of your accounting period. For a 31 March year end, tax is due by 1 January. Large companies with profits over £1.5m pay quarterly instalments instead.
01
Payment before filing
02
Reference numbers and cash planning
Payment before filing
The payment date falls three months before the return deadline, which catches out most first-year directors. You need the figure calculated well before the CT600 is filed, which is a good reason to close the accounts early rather than run to the twelve month limit.
HMRC charges late payment interest from the due date and pays a lower rate of credit interest on early payments. Paying early is a reasonable use of surplus cash if the alternative is a current account paying nothing.
Reference numbers and cash planning
Use the 17 character payslip reference for the correct accounting period. Paying with the wrong reference sends the money to another period and generates chasing letters even though HMRC holds the cash.
Set aside tax as profit is earned rather than at the year end. A separate tax reserve account funded monthly with an estimate from your management accounts prevents the January problem entirely.
Before you act
Rates, thresholds and deadlines quoted here reflect the 2026/27 UK position and current Companies House and HMRC guidance. Check GOV.UK, or ask us, before relying on them for your own company.
Local help
Talk to a limited company accountant near you
We work with company directors across London and Surrey from our office at 12 London Road, Morden, London SM4 5BQ. Pick your area, or send the form below and we will call you back.
Frequently asked
When is my corporation tax payment due?: questions directors ask
What if I cannot pay on time?
Contact HMRC and agree a time to pay arrangement before the due date. Interest still runs but enforcement stops.
Do instalments apply to me?
Only if augmented profits exceed £1.5m, divided by associated companies, so smaller groups can be caught sooner than expected.
Is interest on late corporation tax deductible?
Yes, late payment interest is generally deductible for corporation tax, unlike most penalties.
What records are needed for when is my corporation tax payment due?
Keep bank statements, sales and platform reports, purchase invoices, payroll records, VAT workings, finance agreements and Companies House correspondence. We confirm the exact list at onboarding and identify gaps before a filing deadline becomes urgent.
How much does help with when is my corporation tax payment due cost?
The fee depends on transaction volume, record quality, VAT and payroll requirements, historic catch-up and the level of reporting needed. We agree a fixed scope and price before technical work starts, with published packages available on our fees page.
Can you take over when is my corporation tax payment due from another accountant?
Yes. We request professional clearance, collect the prior records and authorities, check the next Companies House and HMRC deadlines, and give you one clear handover list. The process is normally completed remotely.
Can when is my corporation tax payment due be handled online?
Yes. We work through secure cloud records, scheduled reviews and digital approvals, while keeping a named team available by phone, video call and email. Clients can also visit our Morden office by appointment.
Which accounting software works best for when is my corporation tax payment due?
We regularly work with Xero, QuickBooks, FreeAgent, Sage and connected sales or expense apps. The right setup depends on transaction volume, integrations and the reports you need, not simply the software brand.
What tax deadlines matter for when is my corporation tax payment due?
The relevant calendar may include annual accounts, Corporation Tax payment and return dates, confirmation statements, VAT returns, payroll submissions and Self Assessment. We map the dates from your company year end and registrations.
Is this when is my corporation tax payment due guidance personal tax advice?
No. This page explains general UK rules and common accounting treatment. Your facts, contracts and wider tax position must be reviewed before you rely on a conclusion.
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Check the current rules
Use official information as your reference point.
Deadlines, thresholds and filing rules change. GOV.UK and Companies House publish the current statutory position; advice should then be applied to your company’s circumstances.