The comparison of a loop antenna factor measurement has been performed. One of the motivations for this comparison was that since the last comparison in this field (CCEM.RF-S21.F), several National Metrology Institutes have implemented the calibration capabilities for antenna measurements. The second motivation is that the loop antennas are typically working over a large frequency range, in this case 10 Hz to 30 MHz. For the calibration over this frequency span, two ranges are distinguished: the low frequency range where alternating current (AC) techniques should be used, and the high frequency range where radio-frequency (RF) measurement techniques are applied. The comparison shows that the participants were able to measure within the declared uncertainties. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by EURAMET, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).