Invoices tab is missing from mobile app

It's good to have you here in the QuickBooks Community forum, Littleton. Let's work together to fix your invoice issues.

I've checked our system, and there are no reported investigations about the missing invoice tab in the QuickBooks Online (QBO) mobile application. In this case, let's get your mobile app up and running by rebooting the application. This is the same as clearing the cache from your web browser. The app may become slow or unresponsive due to outdated or corrupted cached files. Thus, it's important to regularly clear the cache to ensure the smooth functioning of the app and avoid issues.

I'll show you how: 

In iOS: 

1. Go to the Menu or Hamburger icon at the bottom right corner, then choose Help & Feedback.
2. Press Refresh.
3. Go to your device settings and click General. 
4. Choose iPhone Storage.
5. Choose the app that takes up a lot of space.
6. Tap Offload App. 
7. Restart your device.

In Android: 

1. From More Options ⋮, select Settings.
2. Click Refresh Data. Then, choose Yes. 
3. Go to your device settings and choose the QuickBooks app. 
4. Press Storage. 
5. Click Clear data. 
6. Restart your device. 

However, if the same thing occurs, you can uninstall and reinstall the application. 

In the meantime, I recommend we open your QBO account using a supported web browser installed on your mobile device. From there, we can start creating invoices to keep track your sales and manage your finances. 

Comment below if you have more questions, Littleton. Stay safe!