Salary sacrifice can be used for any non-cash employee benefits. Your employer might offer you a choice of these benefits. You'll make the biggest savings by utilizing the following benefits as these don't attract any tax or national insurance. These benefits include:
Childcare vouchers (if enrolled onto a scheme before October 2018)
Childcare salary sacrifice (Workplace nursery scheme)
Cycle2work schemes
Pension salary sacrifice
EV Charge scheme
Although you can sacrifice other benefits, such as Home & Tech, Travel or mobile phones, you'll still need to pay tax on them; you can keep any national insurance savings! The Electric Vehicle sheme runs slightly differently - take a look at the more detailed article in this help centre for more detials.
The way tax is collected by HMRC is either via your payslip each payday, usually over the course of 12 months, or in the following tax year by way of a new tax code. A new tax code is issued to you once your employer submits a form to HMRC called a P11D. This declares how much your benefit was, and HMRC will work out how much tax is due on it, then issue you a new tax code.
UPDATE: From April 2027, the following benefits will be included on your payslip to attract tax only, and will no longer be permissible on a P11D return:
Car and Car fuel
Vans and Van fuel
Private Medical Insurance
If you aren't sure how your benefits are taxed, you can speak with your HR or Payroll team and they'll let you know.