Tax Avoidance vs Tax Evasion
Also called: tax avoidance, tax evasion, tax planning
Tax avoidance is arranging your affairs within the law to pay less; tax evasion is concealing income or falsifying facts, which is a crime. The line is legal rather than moral, and it moves: aggressive avoidance schemes are routinely struck down retrospectively by general anti-abuse rules. The practical test is whether a transaction has any purpose beyond the tax benefit it produces.