Won't asign invoice number automatically or manually on app. Said number already exists. I have to do all invoices on computer now which is inconvenient. Please help.

Warm greetings, ljautos. Let's resolve this together so you can assign an invoice number in your mobile app.

Before anything else, please ensure that the assigned number you put doesn't have an existing transaction.

Once you ensure the assigned number doesn't have an existing transaction, create an invoice again. If the issue persists, let's refresh the application to isolate the problem. This is similar to clearing the cache on your web browser.

For iOS:

1. Go to the Help menu.
2. Select Reset App Data.
3. Click on OK.

For Android:

1. Proceed to the Home menu or tap the three dots in the right upper right corner.
2. Tap on Settings.
3. Select Refresh Data.
4. Click on Yes.

On the other hand, you check the status of your invoices in the QuickBooks Online mobile app. This lets you see if they are open, overdue, or paid. 

I'm always ready to back you up if you need further help assigning invoice number in QuickBooks. Kindly tap the reply button to enter your response.