have the option to add additional Sellers in the transaction input

Hi Shaun!

Kallie from the Product Team here at SkySlope. Thank you for reaching out and providing us with this feedback! Once you're in the contacts tab of the transaction file there is the option to add a new seller below the seller contact info. I've provided a screenshot below:
For faster assistance please feel free to reach out to our support team! They can be reached at [email protected] or 800-507-4117. 

Thanks again and have a great day!