This Technical Report outlines recommendations for "smart gas meters", specifies recommendations where there is clear consensus, and identifies areas where there are barriers to standardisation. It indicates how functions may be implemented in a harmonized way if they are selected. It does not seek to select which functions are to be implemented in a smart meter. The report covers simple to complex implementations of smart metering. This Technical Report is applicable to 1st, 2nd and 3rd family gases according to EN 437.