Traveline Information Limited offers several open data options including TNDS, NextBuses API and National Operator Code database (NOC).

NaPTAN is the national system for uniquely identifying points of access to public transport in England, Scotland and Wales.

Open Postcode Geo is a postcode dataset and API optimised for geocoding applications. You can use Open Postcode Geo to geocode a dataset, geocode user input, and therefore build a proximity search. Data is derived from the ONS (Office for National Statistics) postcode database and is free to use, subject to including attributions to ONS, OS (Ordnance Survey) and Royal Mail. Information...