Back up QBO file

The option to back up QuickBooks Online Essentials subscription data files is currently unavailable, @dso0216. 

For now, this feature is only available for QBO Advanced subscriptions. However, you can still obtain a copy of your company data by exporting lists or reports.

Here's how:

1. Click the Gear Icon and then Export data.
2. Select the data you want to export.
3. Click Export to Excel.

On the other hand, you can export non-posting transactions in QuickBooks. For complete guidance, refer to the Export non-posting transactions and attachments section of this article: How to download your data from QuickBooks Online.

After that, you can now cancel your client's QBO subscription and create a backup copy of their QBDT company file as well.

Moreover, let me share some articles that can help you manage your transactions in the future:

• Reconcile an account in QuickBooks Online.
• Back up and restore your QuickBooks Online Advanced Company.

If you have any more questions about backing up your data, feel free to ask here or start a new thread.

@dso0216 

Do you only use single currency? You can purchase a 3rd party service to convert data to QB Desktop and use the trial version to access the historical data for good.