It's best not to instruct the portals until you have all of your properties set up and live. When you are ready, contact the portals themselves and ask them to set up the feed at their end. Expert Agent then sends a confirmation request to you by email.
You have to confirm the request by clicking a link. As soon as you do that, the portal will get your data.
Please bear in mind that this won't be instant - it's best to allow a couple of days for the switchover to be arranged at the portal's end.
For more information on getting in touch with the portals about arranging data feeds, have a look at the Portal Contact Details chapter.