Go to your profile tab in your dashboard
Click the little + icon to add a tab and call it 'Companies/Families/Group' etc. Anything that may have a person paying who isn't traveling.
Then click on 'New Company' or 'New Family' or 'New Group'
A profile page will appear where you will name the company/family/group and then scroll down to 'main contacts' and add your payees' name there.
Go to the trip planner page of your trip, click on the pink 'trip information' button and scroll down to client information and add the company/family/group under 'institution name', it should populate once you start to type it.
Next to it there is a drop down box that says 'select client'. Since you added the payee (ex Jennifer) as a main contact in the steps above, it will show their name.
Press update and go to accounting in the trip planner page and click to 'create new invoice'. On the drop down list, you will see the name of the company/family/group, click that and also click on all the people the company/family/group is paying for.
Since you will have added all those travelers to their reservations before hand, they will show up. The payee (ex Jennifer) will show up below that as the contact person and then you will be able to send the invoice to the same email that you added before in the company profile and her individual profile.