Abstract: Secure printing apparatus, for example printing apparatus of a postage meter, is disclosed in which an ink jet print head with integral ink supply is removable by a user of the apparatus. In order to maintain security of the apparatus, a parking station remote from a printing station is provided for the print head and removal of the print head can be effected only at the parking station through an aperture in a secure housing at the parking station. When the print head is moved to the parking station electrical connection to the print head are disengaged from the print head and means are provided to prevent access to those electrical connections at the parking station.