- Error Code 120:
ShortMessage: You need to create a seller's account.
LongMessage: Before you can list this item we need some additional information to create a seller's account.
As outlined in the error, typically it would be returned via the API when eBay would need some additional information for your seller account. Typically, this can be the automatic payment method, which needs be added/edited directly on eBay and you can double check if the particular automatic payment method, that is set for eBay's selling fees is valid and also make sure the credit card, that is being used for payment method hasn't already expired.