| no. | Participant Type | Short Name | Organisation legal full name | Country |
| 1 | Internal Funded Partner | PTB | Physikalisch-Technische Bundesanstalt | Germany |
| 2 | Internal Funded Partner | Aalto | Aalto-korkeakoulusäätiö sr | Finland |
| 3 | Internal Funded Partner | CMI | Cesky Metrologicky Institut | Czech Republic |
| 4 | Internal Funded Partner | DFM | Dansk Fundamental Metrologi A/S | Denmark |
| 5 | Internal Funded Partner | JV | Justervesenet | Norway |
| 6 | Internal Funded Partner | Metrosert | AS Metrosert | Estonia |
| 7 | Internal Funded Partner | TUBITAK | Turkiye Bilimsel ve Teknolojik Arastirma Kurumu | Turkey |
| 8 | External Funded Partner | CNR | Consiglio Nazionale delle Ricerche | Italy |
| 9 | External Funded Partner | CSIC | Agencia Estatal Consejo Superior de Investigaciones Cientificas | Spain |
| 10 | External Funded Partner | FAU | Friedrich-Alexander-Universität Erlangen – Nürnberg | Germany |
| 11 | External Funded Partner | INFN | Istituto Nazionale di Fisica Nucleare | Italy |
| 12 | External Funded Partner | KBFI | Keemilise ja Bioloogilise Füüsika Instituut | Estonia |
| 13 | External Funded Partner | TUB | Technische Universität Berlin | Germany |
| 14 | External Funded Partner | UdS | Universität des Saarlandes | Germany |
| 15 | External Funded Partner | UNITO | Università degli Studi di Torino | Italy |
| 16 | External Funded Partner | USTUTT | Universität Stuttgart | Germany |
| 17 | External Funded Partner | ZIB | Konrad-Zuse-Zentrum für Informationstechnik Berlin | Germany |
| 18 | Unfunded Partner | INRIM | Istituto Nazionale di Ricerca Metrologica | Italy |