Hello, @thall2200.

As of this time, the ability to automatically include the customers phone number on the invoice is not yet available. What you can do is to add a custom field in your invoices and manually enter the customer's phone number on it.

1. Go to the Gear Icon.
2. Choose the Custom Form Styles.
3. Locate the invoice template you want to modify.
4. From the Actions column, click the Edit link.
5. Select the Content tab.
6. Click the Pencil Icon on the first part of the sample invoice template.
7. Pick the Custom Field link. 
8. Mark the first box and enter its name. 
9. Click Done. 

It's our goal to continue implementing more features into the program based on suggestions from customers such as yourself. Also, our developers frequently review this page to hear what users like yourself would like to see added in future updates.  For news on what's to come, check out our blog (https://intuit.me/2L2zqTv).

The Community is a great resource to explore to find out more about the features and functionality included in the program.