Other questions

I'm here to ensure you can send invoices with attachments in QuickBooks Online (QBO), @Greg142.

One possible reason you're unable to send the documents attached to the invoice could be the file size of the attachments. Check if the file didn't reach the max limit of 20MB. You can edit the file to reduce the size. Then, attach the document again. To be sure it's attached correctly, follow the steps below:

Since you already captured and uploaded the receipts from your mobile app, we can simply add them when creating an invoice. Just click the Show existing link, then Add link for the document. See the screenshot below for reference.

Then, don't forget to check the Attach to email boxes so it will include your attachments in the email. 

If the issue persists, we can perform some troubleshooting steps to see if this is a browser-related issue. To begin, let's access your QBO account in a private or incognito window in your web browser. This will open your account in a clean slate and load fresh data. You can follow the steps shared by RCV above on how to troubleshoot.

If the issue remains, I suggest reaching out to our Phone Support team for further investigation. They can securely initiate a screen-sharing session to identify the issue further and walk you through the resolution.

For future reference, you may check out this article to learn more about customizing templates in QBO: Customize invoices, estimates, and sales receipts in QBO.

Keep us posted about the result. If you have additional questions about QuickBooks attachments, the Community team is always willing to answer them for you.