Did it ever work or is this a new account? Maybe when your user profile was set up, the wrong association was chosen for how it links to your account. Maybe a knowledgeable agent can help here?
@Cblasley wrote: It won't let me pay. It says I'm a secondary user. I am the only user.
If an employee doesn't reply here . . .
Double check your UserIDs on your home system with the Lookup tool at https://idm.xfinity.com/myaccount/lookup. After you enter the requested information you'll see a list of the UserIDs on your account and an indication of which one is Primary. Be aware that the Primary UserID online doesn't always correspond with a name on your billing statement.
If the ID you are using is not Primary, you'll need to log in with the Primary ID. If you need help with that, or if your ID is Primary but you still don't have access, contact one of their reps at the phone number on your bill or 1-800-Comcast, or use one of the other options on https://www.xfinity.com/support/contact-us/ and have them fix the problem.
It won't let me pay. It says I'm a secondary user. I am the only user.
I'd also be able to help you situate your user ID issues! Thanks for posting!
Please send me a private message with your full name for help. Just click my name (Comcast_Support) and then on the next page, you'll see an option to send a private message on the right.