Profits inside the marginal band
A company has profits in the middle range and no or few associated companies.
The tool shows a reduced effective tax position rather than a straight main-rate outcome.
Practical compliance tool
Marginal Relief Calculator
Estimate whether marginal relief applies and show the practical tax effect using profits, period dates, and the associated company count.
Marginal relief is driven by where profits sit between the lower and upper limits once associated companies are taken into account.
Marginal Relief Calculator
Estimate whether marginal relief applies and show the practical tax effect using profits, period dates, and the associated company count.
What the marginal relief result is doing
The result screens whether the profits appear to sit in the marginal relief range and shows the likely Corporation Tax effect at that level.
It is designed for planning and review before the final tax computation is locked down.
Rule summary
Marginal relief depends on profits and associated companies
Marginal relief usually matters where taxable profits fall between the lower and upper limits for the main Corporation Tax bands.
Those limits are reduced where the company has associated companies, so the associated-company count can change whether relief applies at all.
Worked examples
How the result behaves in practice
Associated companies narrow the band
A company has several associated companies, reducing the profit limits available to it.
The result shifts because the same profit figure may no longer sit in the relief range once the limits are divided down.
Turn the result into an action plan
Confirm the profit figure and associated-company count before relying on the relief screen.
Use the broader Corporation Tax liability estimator next if you want the full tax position in one view.
Keep the result as a planning input rather than the final tax computation where apportionments or complex facts apply.
Read the guide
Corporation Tax marginal relief
This guide explains why marginal relief sits between the lower and upper Corporation Tax limits and why associated companies affect the answer.
Assumptions and limits
This tool gives a practical estimate and depends on the assumptions shown below.
Assumptions
- The inputs entered are complete and reflect the facts for the relevant filing, tax, or compliance period.
- The tool is used for a standard scenario rather than a specialist exception, relief, or disputed case.
Limits and rule basis
- This tool does not replace detailed professional review where the facts are unusual or contested.
- If the underlying rule depends on reliefs, appeals, or special handling, the real outcome may differ.