See the article below.  There is a link to the Intuit Markplace for solutions.

Resolution for '800 Employee issue: 'Over 800 Employee Paid this year Message' available: Yes.

The 800 Employee 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 800 Employee issue yourself by looking for a resolution described in the article. If it is a complex 800 Employee issue or you are unable to solve the issue, you may contact us by clicking here or by using other 800 Employee support options.

For more information about resolving issues related to 800 Employee in Quickbooks/QBO or to get support for the issue 'Over 800 Employee Paid this year Message', click the link below: