How to finance buying a car…

WellKnownSid

You can’t salary sacrifice below minimum wage.

Goudy

While it's true a salary sacrifice scheme should not reduce your take home below the lower earnings limit, your personal circumstances may change within contract and take you under the lower earning limit.

When on maternity leave your employer will generally pay their normal proportion of pension contributions, though your pay with a sacrifice might drop below the lower earning limit and effect your state pension.

A period of ill health or unauthorised absence might drop your salary below the lower earning limit as well.

Career breaks are usually allowed under 12 months but that again my drop you below the lower earning limit.
Retire and Return might also drop you below.

There are usually ways out of these but it may involve an early termination fee or paying off the contract pro rata.

MyRealNameToo

Goudy said:

While it's true a salary sacrifice scheme should not reduce your take home below the lower earnings limit, your personal circumstances may change within contract and take you under the lower earning limit.

I believe it certainly can take your "take home" pay below "lower earnings limit".

Minimum wage is based on gross pay not net. Were you to get a silly car as a company car and sacrifice your salary down to NMW the BIK would take your pay down well below what the average minimum wage earner would take home.