Symptoms

On an attempt to add a domain to a G-suite subscription in UX1 to complete provisioning, following warning can be seen:

Action required! Error Create Google subscription With Domain: resource.alternateEmail - Email address contains invalid domain name

The same error can be observed in G-suite endpoint /var/log/aps/apsgoogle.log:

Apr 14 21:02:53 ERROR  24177 |C:1133637|S:1340752|googlecoreservice::_getGoogleExceptionError## Error:  {
  "error": {
    "code": 400,
    "message": "resource.alternateEmail - Email address contains invalid domain name",
    "errors": [
      {
        "message": "resource.alternateEmail - Email address contains invalid domain name",
        "domain": "global",
        "reason": "invalid"
      },
      {

Cause

Google has a limitation that does not allow the admin user to have an email address using the same domain as the one being added to the subscription.

For example, the subscription is placed for domain 'example.com', and the Customer's admin user has the email 'admin@example.com'. The admin's email is used as an alternative email in Google, so it cannot be on the same domain, which causes the error message and provisioning failure. 

Resolution

To resolve the issue, navigate to Billing > Customers > [Customer] > Users > [Admin User] > Edit, and change the email to the one with a domain different to which customer wants to add.