A conversion's processing time depends on several factors including the length of time it takes for QuickBooks Online to export a company file's data, the amount of traffic on both Intuit's servers and Amazon Web Services (which we use to process our conversions), and the size and complexity of the company file itself.
Most of our conversions complete within a couple hours, but large and/or complex files can take several days to complete. You'll receive regular status updates and an email once your conversion is ready.