Short answer
Both corporation tax thresholds are divided by the number of associated companies. Two associated companies means 19% applies only to the first £25,000 of each company's profit, and the 25% main rate starts at £125,000.
Corporation tax
What happens to corporation tax if I have associated companies?
Associated companies divide the £50,000 and £250,000 corporation tax limits, pushing profits into higher rates.
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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Both corporation tax thresholds are divided by the number of associated companies. Two associated companies means 19% applies only to the first £25,000 of each company's profit, and the 25% main rate starts at £125,000.
01
What makes companies associated
02
The practical cost
What makes companies associated
One company controls the other, or both are under the control of the same person or persons. Control includes holdings of associates such as a spouse, civil partner, parent or child where there is substantial commercial interdependence between the companies.
Dormant companies are ignored, as are certain passive holding companies. A genuinely independent company owned by a spouse with no financial, economic or organisational links to yours is usually not associated, but the test is factual, not a formality.
The practical cost
Splitting a business into three companies with £60,000 profit each does not give three 19% bands. With limits of £16,667 and £83,333 each, most of that profit falls into the 26.5% marginal band. The tax cost of the structure can easily exceed its commercial benefit.
Before incorporating a second company, price the association. Sometimes a divisional structure inside one company, or a genuine group with group relief, is the better answer.
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.
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Frequently asked
What happens to corporation tax if I have associated companies?: questions directors ask
Do overseas companies count?
Yes. Non-UK resident companies under the same control are included in the count.
Does an association apply for a whole year?
It is determined by the position during the accounting period, and a company associated for part of a period is counted.
Does association affect quarterly instalments?
Yes. The £1.5m instalment threshold is divided in the same way.
What records are needed for what happens to corporation tax if i have associated companies?
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 what happens to corporation tax if i have associated companies 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 what happens to corporation tax if i have associated companies 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 what happens to corporation tax if i have associated companies 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 what happens to corporation tax if i have associated companies?
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 what happens to corporation tax if i have associated companies?
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 what happens to corporation tax if i have associated companies 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.