When adding my Adwords ID to Ad Grants account, the system says that it is not possible since I have Billing Information included. However, I cannot see any Billing Information in my Adwords account and the Adwords Support Teams has confirmed it by telephone.
2 weeks ago I was able to connect both accounts but since I had a misconfigured one of the adds, Ad Grants rejected the petition. Now that I configured them OK (and Adwords gave the OK), I cannot connect the accounts.
Have you been able to resolve this issue? If not, then you will need to create a new AdWords account using a new email address/Google ID.
The reason for this is because the system will recognize billing information that is tied to an existing Google account and associate that information to the AdWords account you're trying to use for Ad Grants. Due to this, you have to use an email address/Google ID that is not associated with any other Google services.