Verifies an unverified membership user using the Username and GUID (AccountID) parameter if two phase verification of membership users is enabled. Please see the settings document. IMPORTANT! You cannot use this method to return a deleted user to an active state.. 

This function is overloaded. See Also: ActivateUserAccount(Long) 

This method can be accessed through the User.asmx file located in:

~/Workarea/webservices/WebServiceAPI/User/User.asmx

[SoapHeader("AuthHeader")]
[SoapHeader("RequestInfoHeader")]
[WebMethod(MessageName = "ActivateUserAccount By UserName and AccountID", Description = "")]
public bool ActivateUserAccount(string Username, string AccountID);

<SoapHeader("AuthHeader")>
<SoapHeader("RequestInfoHeader")>
<WebMethod(MessageName = "ActivateUserAccount By UserName and AccountID", Description = "")>
Public Function ActivateUserAccount(Username As string, AccountID As string) As bool