I know lots of organizations and websites are publishing some of these but is there an open dataset with at a minimum of location and operator for ATMs in the UK and possible Ireland?
While the data is only as good as the community contributes, OpenStreetMap (OSM) has some ATM data.
In OSM, points can be tagged with "amenity=atm". You can extract these nodes using these steps:
- Download OSM data. This page has a "British isles" extract, among others. This page explains more generally how this kind of data is packaged.
- Download and extract the osmosis command-line java tool
- Run a command such as
./osmosis --read-pbf british-isles-latest.osm.pbf --tf accept-nodes amenity=atm --write-xml british-atms.osm
Osmosis also supports writing to databases instead of XML.
The details available for each node vary widely, but then, you get what you pay for, and as you noted, there are a number of commercial sources for this data.