GoAffPro provides you with the option to enable the W9 form for affiliates.
To enable the W9 form for affiliates, go to the Extras section in the Settings tab of the GoAffPro admin panel.
Here, go to the W9 Form section.
Now, enable the toggle.
The signed W9 forms will be sent to the merchant email address that has been set in the Settings > Notifications > Contact Email section.
The W9 Form section will appear in the Settings tab of the affiliate dashboards.