Problem updating apps after iOS 6 update "Your account is not valid for use in the Indian store. You must switch to US store before purchasing." I am getting the above error while updating apps (I have recently installed iOS 6). My Apple ID was created with country as India. I followed the below steps:


Open the Appstore.
Go to Featured (scroll down to bottom until you see your Apple ID).
Click on Apple ID.
View Apple ID.
Enter your Password.
Once you login it will say your account is transferred to the respective country.


Since the store somehow thought my account was from the US, I approved "the change" to India and signed out and signed in again, still I get the same error.
I had a similar problem trying to update apps because I live overseas in Japan, and after updating to iOS6 it defaulted to the Japanese AppStore. I went to the AppStore, clicked on view AppleID, then it asked for my password which was not recognized as a Japanese account, so after a few attempts, it switched me to the US store and now I can update everything.   Not sure if this will help, but following your steps helped me figure out the solution to my problem! Thanks!!