When creating new listings for eBay, you may run into the error:
Item specific MPN is missing.
If this is the case, all you'll need to do is enter the MPN for each SKU in the listing. If the MPN exists, try saving the listing to resync data. If this does not work, try removing dashes and saving.
For a single listing, this can be found on the Edit Listing page, under the Listing tab and scrolling down:
Until you see MPN under the other Product Identifier fields:
For Variation Listings, you can find the MPN in the same place for single listings, or you can go to the Variations tab and choose MPN from the Bulk Edit dropdown and change them all at once:
Your MPNs need to be unique to each SKU. If you believe your items should not require an MPN, make sure the item is in the correct category, as the requirement is based on category. If they are in the correct category and still require an MPN although you don't believe they do, please reach out to eBay to inquire about an exception!
If you have any questions about MPNs or eBay listings, please reach out to support!