A document file is provided comprising a back (1, 21), a connecting spine (2, 22) with top (3, 24) and bottom (4, 25) walls connecting with the spine to form a three sided enclosure with the back. A cover (5, 26) for the document file has at its free edge opposite its attachment to the spine, a sidewall (6, 30) adapted to form with the back, spine, top and bottom walls in the closed condition of the document file, a closed box. The back preferably has an extension (7, 31) extending along at least a part of its edge opposite its attachment to the spine such that it projects beyond the sidewall of the cover in the closed condition of the document file. The top and bottom edges of the cover preferably have top (10, 27) and bottom (11, 28) wall sections adapted to fit inside or outside the top and bottom walls in the closed condition. The invention also provides a document file blank for erection to form a document file as provided by the invention.