Marketplaces, royalties and specialist businesses lead the UK screen

Baltic Classifieds leads this selection with a 67.56% trailing free-cash-flow margin, followed by Ecora at 64.04%, Bioventix at 60.77%, Thor Explorations at 52.68%, Rightmove at 51.64% and Capricorn Energy at 50.09%. These percentages measure reported cash conversion after productive cash investment; they are not interchangeable with profit margins or recurring distributable cash.

The API supplied candidates across large, mid and smaller capitalization bands. Official annual and interim statements were used to rebuild matched trailing cash flow and revenue, with gross capitalized development, exploration and royalty investment included. The final selection contains 60 UK-listed companies above 15%, spanning the Main Market and AIM, including some foreign-domiciled issuers. This is a verified candidate selection rather than a complete census of every qualifying London company.

YTD performance uses API adjusted quotation-series prices from December 31, 2025 to October 30, 2026. Five-year performance uses October 29, 2021 to October 30, 2026. UK web histories and current prices are cross-checked. N/A means a verified comparable baseline is unavailable. Returns are cumulative and follow the API adjustment conventions; they are not a uniform GBP total-shareholder-return series.

Regular dividend yield uses qualifying ordinary cash paid in the trailing twelve months through October 30, 2026, divided by the snapshot share price in a consistent currency. Special distributions are excluded, including identified components from Baltic Classifieds, Thor, Alfa, Frontier Developments, Goodwin and Seplat. Recurring variable ordinary payments remain included.

FCF/Sales = (reported operating cash flow after cash tax − gross productive cash PP&E and separately classified intangible/software/development/exploration/royalty investment) / reported revenue. Business combinations and financial investments are excluded. Use each issuer’s latest complete matched trailing period available by November 1, 2026. Gross purchases are not reduced by asset-sale proceeds. Annual plus current interim/YTD less the comparable prior interim/YTD is used where needed; annual-only issuers use the latest published twelve-month report.

EBIT/Interest uses statutory operating profit divided by gross expensed interest where separately available. ~ identifies a disclosed proxy, such as cash interest, broader finance costs or an explicit estimate; full calculations and sources are in the Python comments. Thor uses annualized latest-half-year interest because its reported trailing bridge is not a positive charge; Rightmove uses current lease liabilities at an assumed 6% cost. Negative operating profits are retained. Cash-interest classification and lease accounting can affect comparability; lease principal is not reclassified into CFO. P/E is trailing reported earnings, not forward consensus; N/M means non-positive trailing earnings. Cap is GBP, with M/B indicating millions/billions. Valuation and cap use at most one decimal.

Business models and capital requirements shape cash conversion

Classified marketplaces and specialist intellectual-property businesses can generate high cash margins with limited physical investment. Royalty revenue also has a different denominator from mine sales, while gold and copper producers remain exposed to commodity prices, taxes, working capital and project spending.

Gross productive investment is deducted consistently, including capitalized software, development, exploration and royalty purchases. Acquisitions of businesses and financial investments are excluded. Strong cash conversion in a single trailing period can reflect collections of old receivables or customer funding rather than a sustainable operating margin.

Financing and lease obligations require context

The coverage column uses reported operating profit and gross interest where available. Statutory operating losses are retained: positive free cash flow does not justify replacing an impairment-affected operating loss with adjusted earnings. A negative coverage multiple shows that operating profit did not cover the relevant financing charge.

A tilde identifies a disclosed proxy. These include cash interest, broader reported finance costs, Rightmove lease liabilities at an assumed 6% cost, and annualized latest-half-year interest for Thor where the reported trailing bridge does not produce a positive charge. These estimates do not reconstruct observed trailing accruals. Lease principal remains classified as financing cash flow under this screen.

Regular dividends provide a cleaner income comparison

Regular yield counts ordinary cash distributions paid in the twelve months through October 30, 2026. Dividends announced or already ex-dividend but payable after the snapshot are excluded. Recurring variable ordinary payments remain included.

Identifiable special distributions from Baltic Classifieds, Thor, Alfa Financial Software, Frontier Developments, Goodwin and Seplat are excluded. A trailing yield is a historical cash comparison; it is not a forecast of the next twelve months of income.

Valuation and company structure require context

Trailing P/E and GBP capitalization remain in separate columns. P/E is based on reported trailing earnings and may be unusually high after impairment or other exceptional costs. N/M is used for non-positive trailing earnings.

The screen excludes conventional banks, insurers, investment funds, REITs, duplicate share classes and stale listings. London quotation currency is checked separately from statement currency: some retained shares quote in euros or US dollars, while capitalization is presented in pounds.

Cash-flow quality matters more than a single ratio

Free cash flow can be influenced by working-capital timing, acquisition accounting, capitalized development, stock-based compensation and cyclical pricing. A high current margin should be reconciled with the cash-flow statement and compared across several periods.

The strongest candidates are not simply those with the highest percentage. They are businesses able to sustain cash generation, fund necessary investment and allocate the remaining cash without weakening their competitive position.