Abstract: There is disclosed a registration device for use with an envelope inserting machine. The device includes a pair of support members which are L-shaped, and which each have an elongated first portion extending parallel to the feed deck of the machine. A second portion of the members reaches laterally outward and overlies a pair of laterally disposed support members which extend from the feed deck. There is a registration guide member placed over an L-shaped portion of each support member, such that an internal corner of each guide member provides a guide and support for documents moving parallel and between the guides. The guides are clamped to the deck to ensure that documents cannot jam between the guide and the deck.