Freeport and Investment Zones – report the postcode on FPS

Freeport and Investment Zone special tax sites — employer National Insurance contributions relief guidance update

From 6th April 2025, eligible employers operating in a designated special tax site who wish to claim the employer National Insurance contributions relief will be required to provide the workplace postcode for each eligible employee within the RTI (Real Time Information) Full Payment Submission (FPS).

…required to provide the workplace postcode…

This tax relief is not available outside the special tax zones.

If the postcode is not provided where the associated National Insurance Contribution (NIC) categories are applied, then the employer FPS will be rejected.

HM Revenue and Customs (HMRC) has published updated guidance on the requirement at

Check if you can claim National Insurance relief in UK Freeport or Investment Zone special tax sites