It is fundamentally important to make sure that compliance for mining is not issued on the basis of gas content tests that are inadequately located, deficient in frequency or in error. This paper covers some of the issues in relation to location and frequency of cores and validation of gas content test results. Core locations are discussed in the context of recent findings on the reduction of gas drainage efficiency towards the end of in-seam, cross panel boreholes. Some guidelines for sample frequency are given, with increased frequency being required in circumstances involving departure from “normal” conditions as defined through analysis of past data. The gas content validation methodology is set up to provide rulings on gas content test results at the time of reporting, and is intended to aid mine staff in better evaluating test data as part of the process of issuing management plan conformance notices.