Just how have you been trying? Using the Xfinity My Account mobile app (make/model device?) or the My Xfinity website? What error messages or results are you getting? Did it ever work? What kind of account do you have, pre-paid or post-paid?
You can always call in to make a payment if necessary, until your online issue is resolved.
I haven't been able to make a payment online. Very frustrating!
Here are some other options:
Thanks for posting to the Xfinity Forums to make us aware of the issue you're having when attempting to pay your bill online. I'm sure it can be pretty frustrating. I can help troubleshoot to get this resolved if it hasn't been already. Can you please provide more details so I can begin?
Can you send me a private message with your first and last name and the username you are using to login when attempting to pay your bill? I'd like to make sure the username is linked to your account on the backend.
To send a private message click on my name "ComcastChe", then click send a message.