You are supposed to have “pre-printed check stock” which means, Check # is already there at the top, and bank routing and account #s are at the bottom, and this is in MICR (magnet ink encoding).
Pre-printed = already there.
Resolution for 'bank routing issue: 'how can I print check numbers on paper checks' available: Yes.
The bank routing 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 bank routing issue yourself by looking for a resolution described in the article. If it is a complex bank routing issue or you are unable to solve the issue, you may contact us by clicking here or by using other bank routing support options.
For more information about resolving issues related to bank routing in Quickbooks/QBO or to get support for the issue 'how can I print check numbers on paper checks', click the link below: