Once you have an item number, you can use it to search eBay's website for that specific item. It can be done anywhere the main search bar is visible, or by going to 'Advanced search' and choosing the option 'Sort by item number'.

Unless you checked out as a guest, you'll see all your orders in your My eBay > Purchase History. If you checked out as a guest see this link: https://www.ebay.com/help/buying/returns-refunds/returning-item/returning-items-bought-guest?id=4065... Scroll down and click the button to find guest order details.

How to find items you bought more than 60 days ago. You'll see items you bought in the last 60 days when you go to your purchase history. To see older items you've bought, you can change the date range displayed. Go to See orders from at the top of your purchase history and choose the year from the dropdown.

Click on "My eBay" at the upper right corner. Then click on "Purchase History". You are offered choices of "Last 60 days," "2022," "2021" and "2020." Beyond that, you are SOL.