NIM01535 - Class 1 Structural Overview: zero-rate of secondary NICs for Freeport and Investment Zone employees: Freeport Upper Secondary Threshold (FUST) and Investment Zone Upper Secondary Threshold (IZUST)

Section 1(2)(a) and 8 of the National Insurance Contributions Act (NICA) 2022

From April 2022, a new secondary Class 1 threshold was introduced for Freeport employers. This is called the Freeport Upper Secondary Threshold (FUST).

Following the introduction of Investment Zonesthis secondary Class 1 threshold is also available to Investment Zone employers and is known as the Investment Zone Upper Secondary Threshold (IZUST). 

The FUST was set at £25,000 for the 2022 to 2023 tax year and has been frozen at that rate for the 2023 to 2024 and 2024 to 2025 tax years. The IZUST is also set at £25,000.

The FUST and IZUST cap the level of earnings at which the 0% rate of secondary Class 1 NICs applies. Earnings above this threshold will be assessed at the main secondary Class 1 rate of National Insurance. Primary Class 1 NICs remain unchanged.

The prescribed equivalents are:

  • £481 per week
  • £2,083 per month

You can find the NICs category letters for Freeport and Investment Zone employers at NIM01540.

The examples at NIM01570 demonstrate how the FUST and IZUST work.