Land surveyors established in another EU/EEA country are allowed to perform cadastral work in Denmark, under the EU rules laid down in the directives on recognition of professional qualifications and/or the directive on services in the internal market. Before any work commences, the party must make a declaration to the Danish Geodata Agency, cf. section 4, subsection 2-3 of the Chartered Surveyors Act, and section 8 of the statutory order on the licensing of chartered surveyors etc.
For more information on licening as a chartered land surveyor: The Danish Geodata Agency