untaxed
adjective
TAXuk/ˌʌnˈtækst/usused todescribesomething on whichtaxhas not beenpaid, or does not need to bepaid:
Theunderground, untaxedeconomyisestimatedto beworthas much as 40% of theofficialeconomy.
Becausepartof theincomeyou put intoyourpensionis untaxed, the Government is giving you 23p for each £1invested.