In-service testing handbook for gas and electricity meters

Guide to the methodology, overview of timescales and testing requirements for in-service testing (IST).


In-service testing handbook version 3.3

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The in-service testing (IST) handbook is a culmination of the IST group 1 and 2 report and the IST group 3 report. It is designed to provide stakeholders who are undertaking sample testing with an understanding of the sampling methodology, test processes, assessment methods and final assessment criteria. The handbook includes details of IST test stations that have been approved by the Office for Product Safety and Standards for the in-service testing of gas and electricity meters.

The handbook is a working document and amendments will be made when necessary as the implementation of IST develops over time.


If you wish to speak to a member of staff please contact:

Gas and electricity metering team: In-service testing

Utilities Team

Office for Product Safety and Standards
Stanton Avenue

TW11 0JZ

Published 13 March 2014
Last updated 23 August 2018 + show all updates
  1. The In-service testing handbook has been updated to version 3.3
  2. IST handbook updated to version 3.2
  3. IST handbook updated to version 3.1
  4. IST handbook updated to version 3.0
  5. IST handbook updated to version 2.6
  6. Revision of testing requirements for MID approved gas meters after stakeholder review of previous testing done to date to improve the overall process and incorporate best practice and addition of new NMO approved IST Test station.
  7. In-service testing handbook version 2.3 has now been published. It includes the contact details of a new NMO approved IST test station.
  8. First published.