The tool will find listings with identical titles (ignoring punctuation). After that, it looks at price and listing type and will color code the results based on the probability of a duplicate. Results colored white are least likely a problem, followed by yellow, orange, and red as most likely a problem. However, this report is just a guideline and it will be up to you to look more closely at the flagged listings to determine if action is needed.
No more than 10,000 listings can be scanned (each variation is counted toward this total). This tool can not scan the Adult Items section or out-of-stock items. (For more than 10K, Adult, or Stock control items, try the File Exchange version). To scan across multiple seller names, add all the names to the Seller Name field and separate with commas: seller1,seller2,seller3
Fixed price listings: (eBay Policy) An Auction with BIN (fixed price option) is not allowed with an identical fixed price listing. ebay allows one Auction style listing (without BIN) to duplicate one fixed price listing. Beyond that, fixed price duplicates are not allowed.
Auctions: (eBay Policy) Auction Listings that do not have a BIN option may be duplicated within eBay policy, as long as all details are identical (price, condition, item specifics, etc). eBay will then display only one auction at first. When it receives a bid, eBay will expose the next duplicate Auction. Auctions for items that are unique should contain differing information to avoid looking like a duplicate. Duplicate auctions are displayed, but are not flagged here unless the prices are different, in which case you will want to look at the photo or item specifics to ensure the auctions are unique.
There have been reports from sellers whose ended duplicate listings automatically relisted. Typically, those sellers had used third-party listing tools to launch their items, and those tools were automatically relisting the items. In one case, a seller had listed a few test items on a service and had subsequently abandoned the service. But, because their account was still alive, when they tried to end listings months later, those listings kept coming back.
The solution is, of course, to turn off automatic relists within the service before ending the duplicates.
If the service is no longer accessible, then remove the token set by that service within your eBay account settings:
Account > Site Preferences > General Preferences > Third-party authorizations
When creating a NEW listing or using an old listing to SELL SIMILAR, eBay will check whether you are creating a duplicate and will display a warning on the screen. eBay's filter does not appear on the relist function, so exercise care when using RELIST.