NIM01550 | Class 1 Structural Overview: zero-rate of secondary NICs for Freeport and Investment Zone special tax site employees: zero-rate of secondary Class 1 NICs for employees under the age of 21, apprentices under the age of 25 and Armed Forces Veterans
From HM Revenue & Customs · National Insurance Manual
Where:
then employers should claim that relief instead of the zero-rate of secondary NICs for Freeport or Investment Zone employees.