All United States phone numbers must be entered in a 10 digit format, without a country code or preceding "1". 

If needed, additional text can be added to the Donation Form in either the Billing Information Heading, the Phone field, or within the Validation Message. 
To edit the text:

1. Log into the NetCommunity website
2. Navigate to the Donation Form Page
3. Click to Edit the Page
4. Click the gear icon to edit the Donation Form Part
5. Select the Language tab at the top
5. Select Billing Information or Validation Messages from the Category Drop down
6. Edit or add text 
7. Click Save