I'm unable to edit certain invoices in the phone app. Most are fine, but every now and then when I go to edit one I'll get a message saying "Unable to edit."

Hi Tony,

I appreciate you reaching out to the Community and bringing up your concern about the mobile app when editing an invoice.

One of the possible reasons why QuickBooks mobile app unable to edit invoices is that the mobile app has a data issue, thus causing unusual behavior. To verify, we can clear the app's cache files. Doing so helps in fixing any sorts of errors in the system. Before doing so, let's ensure that your mobile app is updated as well as your phone's OS. It helps your application work continuously without interruptions. 

For Android devices, see these steps:

1. From More Options ⋮, select Settings.
2. Click on Refresh Data.
3. Choose Yes.

For IOS devices, see these steps:

1. Go to Settings.
2. Under General, select Storage.
3. Select your QuickBooks app.
4. Click Offload App.

Once done, check if you can now able to edit invoices. If the issue persists, let's try to uninstall and then reinstall the app. 

You can also check out this article to learn how to fix issues or errors upon using QuickBooks mobile app: Fix common errors in the QuickBooks Online mobile app for Android.

If you need additional help with QuickBooks, please let us know. We’ll be right here to further assist. Take care, and I wish you continued success.