Following eBay's Listing Policies
eBay has some hard-and-fast rules about listing your items. When you put items up on eBay for auction, you must list them in the appropriate categories (that only makes sense), and here a few other rules that you should keep in mind when listing. Although this isn't a definitive list of eBay listing policies and rules, it will give you a good working sense of what to look out for.
Take time to familiarize yourself with the User Agreement, which details all eBay policies and rules.
Duplicate listings: eBay allows you five identical listings, no more, at any time. If you're going to list an item that many times, at least be sure to list it in different categories. That's a rule, but it also makes sense. Nothing drives down the price of an item faster than closing identical auctions, one after another, in the same category. eBay also requires that you list your auction in a category that's relevant to your item. (No fashion dolls among the car parts, please, or vice versa.)
Listings with variations: Certain categories on eBay allow you to list multiples of a single item with variations. For example, you may have just purchased a case of baby onesies (those one-piece wrap-around outfits that close with snaps — very popular with the parents of newborns), and you have several sizes and colors to sell. If they're all of the same style, you can put them all in one listing as variations. Currently, listings with variations are only available in certain categories:
Clothing, Shoes & Accessories
Health & Beauty
Home & Garden and most subcategories
Jewelry & Watches
Before you attempt to list an item with variations, it's best to check the eBay Category Look-Up Tool. You can find it by clicking the drop-down menu from the top Navigation bar and clicking Sell→Seller Information Center.
When you list an item in any of these categories, you can indicate that you want to create a listing with variations. On the menu provided, select Yes, then click Continue, and then complete the steps in the List Your Variations tool.
Presale listings: If you're tempted to sell something that hasn't been delivered to you yet, well, as a rule . . . don't. eBay doesn't like it when you try to sell something that's not already in your hands (known as a presale listing). Doing so is a dangerous game to play anyway. In many situations, being the first seller to put a very popular item up for sale can get you some pretty high bids. And if you can guarantee in your auction description that the item will be available to ship within 30 days of the purchase or the auction closing, you can run a presale.