A computer-implemented system is configured to, responsive to failure of anonymity threshold criteria of a payment card transaction based dataset including a geographical region definition including solely a first geographical region, query a geographical information service for data indicative of geographical regions neighboring a first geographical region; iteratively query the payment card transaction based dataset using queries modifying the geographical region definition to include the first geographical region and one or more neighboring geographical regions; test returned results against the anonymity threshold criteria; and responsive to a positive test result, generating an approval indication for a data set.