In order to add a manufacturer contact to your eBay listing, either create a new listing profile within your Freedom account, or directly edit one via live listings / Quick edit.
Once you are within the listing tool area, navigate to stage 5 as shown below:
You will see a new section labelled Item Disclosures, under this there are three new sections.
You will want to click the toggle on the right hand side of the screen, this will then show you the Manufacturer contact form and the Responsible person box too.
Fill in all details required, once you are happy, scroll to the bottom of the page and click next.
This will then save your inputted information.
