With mHelpDesk, you can personalize your numbering to avoid all the confusion!
To update this information, go to Settings > Customize > Numbering (Screenshot A)
From here, update the number you would like your invoices, estimates, and jobs to start at. For your invoices, you can choose a Prefix or Suffix to indicate that the invoice was created in mHelpDesk (Screenshot B).
Remember to save your changes by clicking the blue Save button in the bottom right corner (Screenshot B).