Exemptions and Reliefs: Exemptions: granting/issuing of options
If a share option is itself a marketable security (see STSM022040) then a document which grants or transfers on sale the option is chargeable to stamp duty.
For Stamp Duty Reserve Tax (SDRT) purposes, a call option is a chargeable security but a put option is not. However, the grant of a call option will not result in an SDRT charge as it is the creation of new rights rather than an agreement to transfer a chargeable security.
For further details, see STSM112000.