This FIS fiber transition housing (FTH) provides an optical demarcation and interconnection point for fiber-to-the-premises (FTTP) applications. Suitable for indoor or outdoor locations, the FTH provides physical protection for the transition between provider and customer, and facilitates system testing. Fiber entering and exiting the housing may be secured using the internal lances with the tie wraps. Slack cable is held neatly and securely using the backplate with integrated slack routing/management guides. The backplate also incorporates mounting clips for fusion or mechanical splices. The housings are molded from an engineering grade thermoplastic selected to withstand harsh outdoor environments. These housings may be installed on a wall or secured to a vertical conduit. Unauthorized access is deterred by the security screw latch. For added security, a lock may be installed on the integrated locking hasp.