Many UK companies with profits between £50,000 and £250,000 quietly overpay corporation tax because marginal relief is miscalculated — most often through an incorrect associated-company count. Our free calculator analyses four dimensions of your tax position in about thirty seconds and gives you an indicative estimate of what a specialist review might recover.
The calculator factors in the marginal relief band, associated companies (which reduce the £50,000 and £250,000 limits), augmented profits, and your sector, to flag whether your effective corporation tax rate looks right for your profit level. It is the same starting point our advisers use before a full review.
Owner-managed limited companies, particularly those with profits in the £50,000–£250,000 marginal band, group structures, or associated companies — the situations where the arithmetic most often goes wrong and the cost of getting it wrong runs to thousands of pounds a year.
The estimate is indicative, not advice. If it suggests a material gap, you can apply for a strategic review, where we calculate the precise position on your own figures, including associated companies, close-company rules and augmented-profit adjustments.