ErnestMarples.com serves up free postcode data (just don't tell Royal Mail)
I met Harry Metcalf, one of the guys behind ErnestMarples, at Young Rewired State (a project whose goals were very similar to ErnestMarples.com’s). “We’ll undoubtedly get shouted at severely by the Royal Mail eventually,” he said. “But before we do, it would be great to have lots more people write useful apps that use the ErnestMarples API. If we get shut down, we’ll make lots of noise, and lots of useful apps would make for a much more powerful argument for more open data.” Fighting talk.
Metcalf and his co-founder Richard Pope won’t say where their data comes from, though they claim they “don’t hold a copy of the postcode database ourselves, neither in complete form nor as part of a cache”.
Projects created to date using the ErnestMarples.com API include PlanningAlerts.com, which alerts you of planning applications submitted near you; The Straight Choice, an election leaflet monitoring service and Jobcentre Pro Plus, which provides geographically filtered email alerts for job vacancies.