How does an employer typically gain a financial advantage from an employee using salary sacrifice?

Answer

Their liability for Employer's National Insurance Contributions (NICs) is reduced

Because the employee's formal salary is lower, the employer's corresponding liability for Employer's NICs is also reduced. This saving is often used to fund the benefit provided to the employee.

How does an employer typically gain a financial advantage from an employee using salary sacrifice?
salaryemploymenttaxbenefitsacrifice