This web-page contains links to the key ICO guides on data-sharing. Earlier guides seem to have been replaced by the documents downloadable here (though may still be downloadable from our Information Library).
The main data-sharing Code of Practice contains case studies relevant to sharing of council tax data. However, the housing-related examples in earlier versions are no longer present. Moreover, in its main example, the advice concludes:
Council Tax information is collected under statutory authority so the Revenue Department should seek legal advice before using the information for a non-Council Tax related purpose.