IDA is the Cabinet Office Identity Assurance programme. And it's dead.
Digital by Default News, 15 November 2013, HMRC set to go digital:
But Mr Dearnley, there is no Government Identity Assurance Programme platform. And there isn't going to be. HMRC need an alternative.
Mark Dearnley, the new Chief Digital and Information Officer for HMRC, announced at the Ignite conference in London that HMRC will “become a fully accessible digital business.” ... He went on to say: “The multi-channel digital tax platform will have security at the heart of it. The new Government Identity Assurance Programme platform will be part of that".