Defines terms relevant to capital gains relief for business disposals: '51 per cent subsidiary' (per s9(1)(a)); 'development land' (per s648); 'group' as a holding company and its 51 per cent subsidiaries; 'holding company' whose business is wholly or mainly holding those shares; 'qualifying business' excluding holding assets as investments, development land or land development/letting; 'qualifying group' where each 51 per cent subsidiary carries on a qualifying business; 'qualifying person' as a director or employee spending not less than 50 per cent of working time in a managerial or technical capacity and serving continuously for 3 years in the 5 years before disposal; 'relevant company' and 'relevant individual' defined by beneficial ownership periods; 'working time' specified; periods under sections 586 and 587 are taken into account for qualifying periods.

'Chargeable business asset' comprises assets (including goodwill) used in a qualifying business and holdings of ordinary shares where an individual has owned not less than 5 per cent of the ordinary shares for a continuous period of not less than 3 years and is a qualifying person. Exclusions include investment holdings, development land, assets producing no chargeable gains, and certain disposals to companies where the individual is connected immediately after (subject to subsection (8)). A relevant individual’s chargeable gains are taxed at 10 per cent; disposals 1 Jan 2016–31 Dec 2025 attract 10 per cent on aggregated gains up to €1,000,000 with excess taxed at the rate in section 28(3), and disposals on or after 1 Jan 2026 use aggregation rules with a €1,500,000 threshold. Section 597A applies where it gives a lower tax liability; section 600 proportionality, an anti‑avoidance rule on connection, and a bona fide commercial reasons exception are provided as specified.