Amazon error 4400: Not approved for seller-fulfilled offers in this category
What does it mean?
Your approval covers fulfilment by Amazon only.
How to fix it
Switch to FBA or request approval; do not send a seller-fulfilled quantity for FBA SKUs.
Where do you fix it?
- In Seller Central: application or setting
- 8026Not authorised to list in this category
- 6024Not authorised to list in this product line, category or brand
- 6039Approval is needed for a restricted sub-category
- 6042The item is restricted for this product type
- 18299Not currently approved to sell this product
- 90202A restriction is in effect for this item
- 8059The item is restricted by Amazon in your region
- 8543The SKU matched an ASIN that has listing restrictions
Source
Summarised in our own words; Amazon's page is leading.