SIP usually refers to a “share incentive plan”, a tax‑advantaged employee share scheme used in the UK to allow employees to acquire shares in their employing company or its parent. It is a statutory concept in the UK, governed principally by Schedule 2 to the Income Tax (Earnings and Pensions) Act 2003 and supporting HMRC guidance. In practice, SIPs are used in corporate, employment and tax work to structure equity participation for employees on favourable income tax and National Insurance terms, provided the plan is formally approved and operated in accordance with the legislation. They commonly involve free, partnership, matching and dividend shares, held in a SIP trust for specified minimum holding periods. SIPs are widely encountered in mergers and acquisitions, group reorganisations, listings and private equity transactions, where lawyers must consider the impact on existing SIP awards, leaver provisions, change‑of‑control clauses and tax consequences. The statutory SIP regime applies to employees in companies within the charge to UK corporation tax, and thus is relevant in England and Wales, Scotland and Northern Ireland. Ireland has its own, broadly similar but distinct, legal and tax framework for employee share schemes; the UK SIP rules do not apply there.