The initial IFC2x release has been published in Nov 2000 as the first IFC platform release. It introduced the concept of a core model and domain extensions. It had been the first IFC release that got a broader implementation base and implementations had been certified using an earlier certification program.

Issues with the initial IFC2x release have been fixed within the IFC2x Addendum 1 release, published in Nov 2001. The required fixes led to an upward compatible schema change. The IFC2x Addendum 1 release had been recommended for implementation and certification.

Since July 2007 the IFC2x release (as all previous releases of IFC) has been superseded by the IFC2x3 Technical Corrigendum 1 - it is strongly recommended to download and use IFC2x3 Technical Corrigendum 1 from now on.