IEC 62055-31:2005 applies to newly manufactured, static watt-hour payment meters of accuracy classes 1 and 2 for direct connection, for the measurement of alternating current electrical energy consumption of a frequency in the range 45 Hz to 65 Hz that include a load switch for the purpose of interruption or restoration of the electricity supply to the load in accordance with the current value of the available credit maintained in the payment meter. It does not apply to static watt-hour payment meters where the voltage across the connection terminals exceeds 600 V (line-to-line voltage for meters for polyphase systems). It applies to payment meters for indoor application only, where the payment meter shall be mounted as for normal service Functional requirements that apply to payment meters are also defined and include informative basic functional requirements and tests for the prepayment mode of operation in Annex A. This bilingual version (2013-05) corresponds to the monolingual English version, published in 2005-09.