are item numbers unique numbers?

[cooltronix]

Just a silly beginners question, are item numbers unique numbers or do they repeat eventually? Or do they get eventually recycled? I believe they are unique, or?

Just play a bit with a database and want to use the item# as unique identifier.

[slippinjimmy · Accepted solution]

Over the years eBay has added digits to Item numbers, originally it was 9, then it became 10 which lasted for a couple of years before they changed to 12.

At some point they will need to go to 13 but that won't happen anytime soon.

The numbers never repeat.

[slippinjimmy]

You can use the number but understand that if you run MQ listings  you will have more than 1 sale referencing 1 inventory item or listing.

I would suggest including the item number in your database along with a self-generated number (sku) connected to the inventory item and perhaps a transaction number as well.

[cooltronix]

I could use the transaction number for that, that is unique and for one sale only. However, right now I just look at auctions, and they are usually single items and single transaction.

BTW, it's not in anyway related to my website.

[slippinjimmy]

I understand, I was in a similar situation years ago, I also only did Auctions and Single unit FP listings but then one day I did a MQ listings and I got thrown for a loop because I had the duplicate eBay numbers and that listing number was the key field on which all my db queries were done.

I almost sent order #2 to buyer #1 (who I had already shipped to).

[cooltronix]

So I guess you also work with the eBay API directly. It's fun, isn't it?