Hello there, gangogreen940,

Sending invoices from QuickBooks Online via text attachment is unavailable.

For now, I recommend checking the Apps menu or  QuickBooks App Center. From there, you can integrate a third-party app that can help you in sending your invoices through SMS.

Here's how:

1. Click Apps in the left navigation menu.

2. Click the Browse Category drop-down menu, select Data Sync.

3. Select the app you want to integrate.

4. Click Get App Now and complete the following on-screen instructions.

Check out this article for future reference: How to let customers pay their invoices online.

Reach out to the Community if you have additional concern.