Choosing a User ID
A User ID is the unique name you use to identify yourself on eBay and can be seen by all eBay users. Your User ID is displayed when you buy or sell on eBay or communicate with other eBay members. However, other users won't be able to see your real name and other personal information.
You use your user ID and password to sign into eBay. When you register, choose a User ID that you like and that you'll remember. For example:
You might use words identifying your favourite collecting area, your business, or your occupation.
You could refer to your location and call yourself jurong_jimmy.
You can refer to your own sense of style and choose happyhady.
Remember that User IDs can contain letters (a-z), numbers (0-9), and/or some symbols, and must be at least six characters long. The most secure User IDs contain a combination of all the above options.
What You Can’t Include in a User ID
The following list includes characters and elements that you cannot include in a User ID:
The @, &, ‘, (, ), <, or > character.
Spaces or tabs.
Tip: You can use a hyphen to represent a space.
Elements that imply an email address or Web address (for example, xyz.com), including but not limited to .com, .net, .org, .edu, or any variation of such (for example, _com or -com). Your user ID can, however, contain an element of an email address or Web address (URL) that, when viewed outside the context of the email address or Web address, identifies you or your brand (for example, xyz).
Consecutive underscores __.
An underscore _, hyphen -, or period . at the beginning of a user ID (for example, -pezcollector).
The word eBay (only eBay employees can use the word eBay in their User IDs).
The letter e followed by numbers.
Obscene or profane words that violate eBay's guidelines. See eBay’s rules on profanity.
The same user ID as another seller or similar to an eBay Store name.
A term that is similar to, or might be confused with, a third-party's trademark or brand (for example, CocaColaSeller).
Note: If you received the message You have entered a user ID that is not allowed, you may have included one or more characters or spaces that are not allowed in a user ID.
You can only change your user ID once in a 30-day period. This is to prevent confusion for other eBay members.
About Creating eBay Store Names
Store names are another form of identification on eBay. More flexibility is possible in creating Store names. For example, spaces are allowed in Store names, as are symbols such as &; however, eBay Store names must otherwise follow the same guidelines and restrictions as eBay User IDs.