Qb online mobile app not showing complete list of vendors or customers, can not even make invoice or enter expense, this has been for about a week now.

Let me first welcome you here in the Community, brianmann-et.

I'll help view all your vendors and customers, and create transactions in the QuickBooks Online (QBO) mobile app.

This issue is probably caused by the stored junk files in the system. We can perform some basic troubleshooting steps to rectify this.

Here's how:

1. Open the QBO mobile app
2. Select Help.
3. Click Reset App Data. 

Once done, re-open the app and log back into your account. Then, check if you can already see all your vendors and customers, and create transactions. If you're still unable to see them, you might need to uninstall and reinstall the app to start a clean slate.

For more information about the feature available on mobile devices, I recommend checking out this article: Mobile App Features.

I also suggest visiting our QuickBooks blog from time to time. This way, you'll be able to stay updated with all the product news and improvements.

Lastly, please know that you can always find me here if you have any other concerns or follow-up questions. Our assistance will be posted on time.