It depends a lot on what the open bill is for.

First thing would be to get an account print out from the vendor, with a start date prior to the date of the bill.  then run your transactions for that vendor against their payments received/your payments.

Resolution for 'account print issue: 'How to get rid of an open balance under Pay Bills section' available: Yes.

The account print issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the account print issue yourself by looking for a resolution described in the article. If it is a complex account print issue or you are unable to solve the issue, you may contact us by clicking here or by using other account print support options.

For more information about resolving issues related to account print in Quickbooks/QBO or to get support for the issue 'How to get rid of an open balance under Pay Bills section', click the link below: