You may find the following resources helpful in your work:
- DAWA - public API providing Danish address verification and sanitation
- Download of DK post codes - static files
- CVR API - public API for verification of Danish Business Codes
- CPR explanation.
Testing with CPR
Below is a set of valid Danish NationalIDs that can be used for testing purposes (source sundhed.dk):
Valid Danish NationalIDs (CPR) for testing purposes
You may use these dates combined with any four digits e.g. 0101601234: 010160 010164 010165 010166 010169 010170 010180 010182 010184 010185 010186 010187 010188 010189 010190 010192