To further investigate why you're unable to deposit a check using the mobile app, I recommend contacting our QuickBooks Live Support Team, fordfire65.
To get in touch with them, click the Help button located in the top-right corner of your QuickBooks Online screen. Next, select the Assistant tab and type Talk to an expert to receive various support options. From there, you can choose your preferred method of assistance, either through Chat or Callback.
To check when Live Support is available, refer to our support hours here: Get help with QuickBooks products and services. Ensure that you select QuickBooks Online as your product.
If you have any other QuickBooks-related questions, feel free to reply here.
