STS Association Wiki



The specifications relevant for the implementation of an STS compliant system are listed in the table below. The table also shows where the specifications may be obtained from.

​​Companion Specifications

Companion specifications are enhancements to the international standards, developed by STSA working groups and published by the STSA, which are destined for inclusion into future releases of the international standards and may be used for development and enhancement of payment systems.

​Which edition of a specification should be used?

It is imperative that the latest version of a specification be used for development. The test houses will always use the latest version for compl;ience testing of a product. If there is any uncertainty into which version is the latest, you may visit the STSA website at, or contact technical support.




​Specification Number

Title andDescription​

​Specification Type

Available from​

​IEC62055-41 Ed2 2014 ​Electricity metering – Payment systems –
Part 41: Standard transfer specification (STS) – Application layer protocol for one-way token carrier systems​
​International Standard ​IEC Webstore
​Electricity metering – payment systems – Part 51: Standard transfer specification (STS) – Physical layer protocol for one-way numeric and magnetic card token carriers
​​International Standard ​​IEC Webstore
​STS101-1 ​Physical layer mechanical and electrical interface for virtual token carriers​ ​Companion specification ​STSA
​STS101-2 ​Physical Layer Protocol for a two-way virtual token carrier for remote connection over DLMS/COSEM ​​Companion specification ​STSA​


IEC62055-41 - Changes from ​Edition1 to Edition 2


​Edition 2 of the IEC62055-41 was published in 2014. The changes from Edition 1 to Edition 2 are summarised below.

IEC62055-41 - Changes from Edition 2 to Edition 3

Edition 3 of the IEC62055-41 specification is due for publication in 2018.