Harry,
eBay uses more than the IP address to suspend accounts. An IP address is the location of a computer’s connection to the internet. IP addresses can be static meaning they don’t change, or change frequently. Because they change, someone else may end up with the same IP address. This means there is not enough certainty to associate eBay accounts using just the IP address.

The name used to create the account is a big part. So is the physical address. If the first name is different, but the IP address and physical address are the same they might ask for clarification in the form of a faxed copy of a drivers license. But that only happens when people started listing the same auctions on the new account.

I’d bet eBay also uses information about your computer. Your computer shares information with the web sites it visits. Things like the user name, browser type, operating system, cookies, and screen resolution. These don’t seem to play a big role in associating eBay accounts because there is a possibility two users could be using the same computer. If it does play a role it would result in a request for a faxed copy of a driver’s license.

Another factor seems to be when the accounts are created. If an account is suspended and a new one shows up selling similar items with a similar name, address, and IP, the new account is suspect.

So that’s six things we know eBay uses to associate accounts.

The last one how products are offered hasn’t be covered yet. I’ve seen people take auctions ran on a suspended account and list them on a new account without making any changes. Each auction is different because each seller is different. The products sold might be the same, but the description, images, and layout will always be different.

Use the list of six items eBay might use to associate accounts to remove as much overlap as possible.