Unable to preview invoices on iOS app. Just says preview unavailable

Welcome to Community, broganballweg-gm. 

I have a few steps to share to get your mobile app up and running.

If you're using the QuickBooks Online Desktop App for Mac, you can reset the app's data by going to Help at the top and select Reset App Data.

If you're using the QBO mobile app, I suggest uninstalling and reinstall the app. You may also need to update your phone's operating system to the latest version. This fixes the unexpected behavior of the product.

Here's how:

1. Tap and hold the app on your phone.
2. Drag the app to the Uninstall section.
3. Click Yes to confirm.

Once you have uninstalled the app, you can now reinstall. Make sure you're using the same credentials you used when signing in on a web browser.

For future reference, visit this article: Customize invoices on the QuickBooks Online mobile app. This will guide you on how to personalize your sales form. Also, it contains steps on how to change your sales form delivery method on mobile.

Feel free to add a comment below if you have any other invoices concerns. We're always here to help!

I tried uninstalling and reinstalling the app. It made no difference

Thanks for getting back here, @broganballweg-gm.

Have you also tried to clear the data on your QuickBooks Online (QBO) Mobile app? There are times that the store cache on your app can cause errors when using it. If not, you can follow these steps:

1. In your QBO app, go to the Menu ☰ option.
2. Click Help & Feedback and choose Refresh Data.
3. Then, select Refresh.
4. Once done, let's clear the cache on your device settings.
5. Click Setting General iPhone Storage and look for the app that's taking up a lot of space.
6. Select Offload App to free up the storage.

After that, attempt to preview an invoice again. If the same result, let's also check if you can successfully preview invoices using a web browser. If you encounter no error, I suggest reaching out to our Customer Care team to further investigate what causes the issue.    

Customizing your invoice forms to reflect more of your business identity is easy with QBO. To get started, please head to this article: Customize invoices, estimates, and sales receipts in QuickBooks Online. This page will also guide you on how to upload a logo and reorder columns.

I’m always here in the Community if you need more help viewing your invoices. Just post a reply below to notify me of your response. Take care.