Weighted Average Cost of Capital (WACC) meaning

The blended rate of return a business must offer to all providers of finance—equity holders, lenders and preference shareholders—weighted by their proportions in the capital structure. In practice, WACC is used as the discount rate in discounted cash flow (DCF) valuations for mergers and acquisitions, fairness opinions, regulatory price controls, project finance, impairment testing and in litigation (for example, valuation and competition law damages). WACC is not defined in UK or Irish legislation or case law; it is a financial valuation concept applied across legal contexts. Regulators (for example, sector regulators and the CMA/CCPC) often publish WACC methodologies for price control purposes, which may differ by sector and over time. Key features: - Cost of equity (commonly estimated using CAPM: risk‑free rate, beta and equity risk premium). - Cost of debt (reference rate plus credit spread), typically adjusted for the corporation tax shield. - Cost of preference shares (preferred capital), where relevant. - Gearing based on market values, with currency and inflation consistency. Usage and calculation principles are broadly consistent across England & Wales, Scotland, Northern Ireland and Ireland, though input assumptions (tax rates, risk‑free curves, regulatory parameters) are jurisdiction‑specific and should be evidenced with sensitivity analysis.