One of the main causes of QuickBooks Payroll Taxes Not Calculating Correctly is incorrect tax rates; other possible causes include outdated software, misconfigured employee profiles, and outdated tax tables. Most problems can be fixed by making sure that software updates are applied correctly, accurate employee data is entered, and payroll taxes are calculated accurately and in accordance with tax laws. Our QuickBooks Experts Team can also be reached at 1-800-845-9666.