The Trading Partner Contacts session allows a contact to function as a representative to multiple trading partners. This is useful if a supplier has multiple trading partner IDs and would like to assign one contact to represent all trading partner IDs. It is also useful if a 3rd party contact is being used to manage a different trading partner contact. The 3rd party contact would still belong to his 3rd party trading partner, but could also represent another trading partner. (i.e. a container maintenance provider's manager may need to have his customer's trading partner access) 

To add a contact to a trading partner: 

1. Using the Advanced menu, click People > Trading Partner Contacts
2. Click Select Contact. 
3. Search for the contact you would like to add. 
4. Click to select the contact. 
5. Click Select Trading Partners.
6. Select the trading partner. 
7. Click Add Selected Partners. 
8. The selected contact will now be tied to the trading partner.