Use of the Trading API to exchange messages between eBay members depends on the relationship between the respective members:

  • No existing relationship

    All eBay users can send messages to other eBay users through the eBay marketplace, even if there is no established relationship between them. These messages will appear in the My Messages InBox.

    If a seller receives a question about an active listing from someone who has sent a message via the marketplace the seller can use AddMemberMessageRTQ to reply to that question. No order or bidding relationship is required. The seller also has the option of posting the question and response in the listing for all prospective buyers to see.

    For additional information, refer to:

  • Order relationship

    An order relationship exists between two members when one is the seller of an item and the other is a buyer/winning bidder in an auction. A single or multiple line item order is created once there is a commitment to purchase from the buyer regardless of whether payment has been made.

    Refer to AddMemberMessageAAQToPartner for additional information.

  • Bidding relationship

    If the item is in the Motors or Business & Industrial categories, and if one member is the seller and the other has made a bid on the seller's item, GetUserContactDetails can be called for either user to obtain the other's phone number, if available.

    For additional information, refer to:

Retrieve messages

Any user can retrieve their messages via My eBay on the eBay marketplace.

Messages can also be retrieved for any user via GetMyMessages or GetMemberMessages. Refer to GetMyMessages and GetMemberMessages for additional information.

eBay users can subscribe to the MyMessages platform notification in order to be automatically notified when specific kinds of messages are received in their My Messages InBox. Refer to MyMessages for additional information.