Can I upload my listing to my company website before uploading it to 3rd party websites?
Yes this is possible. Follow the instructions on How to Disable Automatic Update to Feeds/Portals and disable / deactivate all website except your own.
If you wish to send the listing to 3rd party websites at a later time.
1. Go into the Listing then Websites tab and click on "+ Active" button for the appropriate website
2. Click "Update" button to send it to the websites for the first time
1. Go into the Listing then Websites tab and click on "+ Active" button for the appropriate website