“Most credit-card accounts have a single owner. Others may appear on the account, but are simply authorized users, not owners. For instance, your spouse might own the account and add you on as a user.
If you aren’t sure if you have a joint account or an authorized user, call the credit-card company and ask about the account. If you aren’t an owner, they may refuse to speak to you about account details. If they do, ask about liability. If it’s shared, you’re a joint owner.” -David Eifrig
