Invitbox calls them “Supplier Cards”.
Xero knows them as the “Contact” for your supplier.
For a detailed explanation of “Supplier Cards” in invitbox, please refer to the Suppliers user guide.
In summary, in order to export a bill to Xero you must first associate the Supplier in invitbox with a Contact in Xero. When invitbox connects to Xero a Supplier Card is created for each of your Contacts in Xero.
At the time of writing (28th April 2014) Xero does not allow you to flag a contact as being a supplier without actually associating a bill or an expense to it. For this reason, if all your Contacts have not been updated to be Suppliers in Xero, you should import all your Contacts into Invitbox by clicking on the 'New to Xero?' link on the Admin > Supplier Cards screen (see image below). This will allow you to add a Contact as a Supplier in Invitbox and when the bill is exported, the Contact in Xero will automatically be updated to a Supplier:
If you are not new to Xero and your contacts have bills associated with them, then you can click on the green 'Import From Xero' button (see image below)
But what if you are not new to Xero and you have new contacts you want to import?
Then you can still click on the 'New to Xero?' button and it will allow you to import your Suppliers and Contacts (see screenshot of message below)
Did you know you can create a new Xero supplier whilst in Invitbox?
If invitbox receives a bill from a new Supplier that you have not added to Xero, you can simply create a new Xero Supplier Card manually within invitbox whilst you are creating the new Invitbox supplier. As the image below shows, next to the empty Supplier Card field is a greensymbol. Click this to add a new Xero supplier card, then upon bill export, Xero will create that new Supplier automatically for you in Xero. You do not need to create the Contact first in Xero.
You can also create a new Xero Supplier Card manually within invitbox via Admin tab> Under the heading 'Accountancy Software Settings'; Supplier Cards> click Add (see image above), and then you need to associate the new Supplier Card to the Supplier in invitbox via Admin > Suppliers. (yellow field in image below)