eBay states that you can only dropship if you source items directly from a wholesale supplier with whom you have a formal contract. Buying an item from a retail store like Walmart and having them ship it to your customer is not allowed.
The Risks Involved
Account Suspension: If eBay detects that you are fulfilling orders from another retailer, they can end your listings, lower your seller rating, or ban your account.
Stock and Price Changes: Walmart prices change often, and items go out of stock quickly. If an item sells on your eBay store but is gone on Walmart, you must cancel the order, which hurts your seller profile.
Branding and Packaging: Customers will receive their items in Walmart boxes or with Walmart invoices, which often leads to complaints or returns because they thought they bought from an independent eBay seller.
How People Try to Do It Anyway
Some sellers use automated software like AutoDS to track stock and copy listings from Walmart to eBay. However, relying on automation does not make the practice compliant with eBay’s terms of service.