Salary sacrifice allows an employee to give up part of their salary in return for a non-cash benefit from their employer like pension contributions. This reduces income tax and employee NI contributions, resulting in higher pension contributions at no extra cost to the employer. HMRC views this as a legitimate way to take advantage of tax exemptions for certain benefits, not tax avoidance. Employers can implement salary sacrifice by changing employment contracts with employee agreement for at least a 12 month period.