An example method includes receiving image data captured by a sensor on a robotic device. The robotic device is in a warehouse, including multiple inventory items stored at storage locations in the warehouse. Each inventory item has an on-item identifier that identifies it in a warehouse management system (WMS), each storage location has a storage-location identifier that identifies it in the WMS, and a first on-item identifier for a first inventory item is associated in the WMS with a first storage-location identifier for a first storage location. The method includes analyzing the received sensor data to detect an identifier captured by the sensor. The detected identifier includes one or both of the first on-item identifier and the first storage-location identifier. The method includes determining a warehouse location associated with the detected identifier and, based on the warehouse location, determining a location of the robotic device within the warehouse.