You can’t merge (or rather, link) two accounts unless they have the same email address.
As you can’t register another eBay account using an email address already in use, there’s only one scenario in which the “same email address” comes into play. That’s if you log into eBay via your social media (Facebook account, Google account, or Apple account). You can link your usual username-and-password eBay account with an eBay account that you’ve created via the social media login method.
(Caveat: It’s not 100% clear whether you can link the existing eBay account with one created with your social media accounts if the social media account uses a different email address to that used with your existing eBay account. I can’t test this as I’ve no intention of providing eBay with any details of any social media accounts I may or may not have.)
❝Linking your eBay account to your Facebook, Google or Apple account
If you already have an eBay account, you can link it to your social accounts:
- Go to Sign-in and security.
- Go to Social sign-in and select Edit next to Facebook, Google or Apple.
- Sign in to your eBay account.
- Select Continue with Facebook, Continue with Google or Continue with Apple.
- You'll need to sign in to your social account with your email address or phone number and password, or your Apple ID.
- Select Continue.❞
Both of the links below give you all of this information.
Creating an eBay account (incl. via your social media account)
Logging into your eBay account
