An IDAP file is a package used by InDesign, a desktop publishing application used to create professional page layouts. It contains a subset of an InDesign document (.INDD file) that has been modified by an editor. IDAP files are used to import edited page content back into the original InDesign document.

Before creating an IDAP file, an editor first receives an .ICAP file, which has been exported from InDesign. The editor modifies the ICAP file using Adobe InCopy, exports the IDAP file, and then sends the IDAP file to the original InDesign sender. NOTE: IDAP files are used by InCopy and InDesign CS4 and later. The CS3 version uses the .INDP extension.