The technology of Eddy Current Arrays has advanced considerably in recent years. In several trials, superior performance compared to magnetic particle testing was shown. In response, ASME has published new articles on Eddy Current Array (ECA) testing in the 2019 edition of the BPV, and IIW has started a working group to develop ISO standards for the use of eddy current array testing in lieu of magnetic particle testing. Significant interest has been indicated by stake holders, including manufacturers, end-users and regulators. In the paper, the work performed in the IIW working group will be presented. This includes a literature survey on the relative performance of eddy current array testing and magnetic particle testing. In particular, the performance in terms of probability of detection and characterization will be explored. The technical background of performance differences with conventional eddy current testing, magnetic particle testing and dye penetrant testing will be evaluated. Conclusions are drawn on the most important properties to be treated in a new ISO standard in the ISO 17635 framework. The scope of the IIW working group includes a general standard, a weld testing standard and acceptance criteria. Finally, the issues discussed in standard development will be presented and the resulting formulations explained. Comparisons will be made between the ASME and IIW/ISO resolutions.