Abstract: Systems and computer-implemented methods for predictive routing of item packages within a materials handling facility are disclosed. A predictive router may operate in conjunction with a container recommender, and both may be components of a facility management system. The predictive router may determine a routing destination for an item package dependent, at least in part, on the size and/or dimensions of a container that was recommended for handling the item package. The routing destination may be a shipping line customized for preparation of packed boxes of a particular size or in a particular size range for shipment. An optional scanner may attempt to determine the size of the actual container being used to ship the item package, and the predictive router may update the routing destination if the actual container does not match the recommended container. The predictive router may also consider special handling instructions when determining a routing destination.