App Store: "To update this app, you need to accept it on the Account page" I'm trying to update Keynote in the Mac App Store and I get this message:


  Unable to update “Keynote”
  To update this app, you need to accept it on the Account page in the App Store.


I get the same message for Pages and Numbers.

Where is the Account page?
While Simon's answer is correct, the reason this may be appearing for you is actually because you have those apps pre-installed. I ran into a similar situation just now. Despite already having those apps tied to my Apple ID, there's something about this having them pre-installed on my machine that breaks down.

Simply delete those apps. You'll be able to redownload and update them from that same "View My Account" page with no issues after that.

Tip: For those unable to reinstall (work computer, etc.) if you simply delete then "Move Back" from the trash you will achieve the same result.