The real thing, not an approximation: this page calls the same computation engine that prepares our CT600 returns — small profits rate, marginal relief, associated companies, financial-year straddling and full mortgage-interest deduction included. Nothing you type is stored.
Companies under the same control ("associated companies") divide the £50k/£250k thresholds. Usually 0.
Revenue repairs only — not improvements.
Ground rent, service charges, accountancy, admin.
Interest only, not capital repayments — a company deducts this in full (no Section 24 restriction).
The same engine prepares FRS 105 accounts, the tax computation and the CT600. First filing free; the eligibility check takes 60 seconds with no signup.
File this return