ETASSUM48280 - Company Share Option Plan (CSOP): Taxation: Readily Convertible Assets (RCA’s)
For PAYE/NIC to apply in respect of a non tax relieved share option gain the shares must constitute Readily Convertible Assets (section 702 ITEPA). In simple terms this means that there must be trading arrangements in place (or that will come into place) for the shares acquired on exercise of the option or alternatively (from 10/07/2003) that the shares would not qualify for CT relief in accordance with Sections 1001-1038 CTA 2007 (see BIM44265).
More detailed guidance on RCAs can be found at ERSM170030.