QuickBooks Online uses a timeout feature for your security. This feature helps prevent unauthorised persons from accessing your data when you're away from the computer.
So, if you are working in QuickBooks Online and is inactive for a period of time, you will see a "time out" security message. The default setting is 1 hour, but that setting can be changed for up to 3 hours.
To change the time out duration in QuickBooks Online
Select the Gear icon at the top then Account and Settings.
Select Advanced from the left navigation menu.
Select the pencil icon from the Other preferences section.
Choose 1, 2, or 3 hours from the drop down menu next to the "Sign me out if inactive for" preference.
Select Save then Done.
A few things to remember:
QuickBooks Online measures your time of inactivity from the last time you moved your mouse, clicked, or used your keyboard on any transaction form.
If you are timed out, sign back in to your company to continue where you left off.
The timeout setting can only be changed by the Master Administrator and it applies to all company users.