If you’ve been using Quicken for Windows or Quicken for Mac 2007 with Quicken Bill Pay, you must create a new account for this version of Quicken. Quicken for Windows/Mac 2007 uses an entirely different system and website than the new Quicken. Make sure you are using the right one by going to quickenbillpay.com first and then choosing following the steps to get started or go directly to the Switching to Quicken 2018 Membership article.
If you set up a new Quicken Bill Pay account, remember to cancel your old service or you will continue to be billed from the old account.