They state:The Role of Tiferes Bais Yisrael
Proper guidance is crucial when a non-Jewish spouse sincerely seeks a halachic conversion.
To assure full acceptance into any Jewish educational system or community throughout the world, including Israel, the conversion must adhere to the requirements and standards of Jewish law, as established by recognized Torah authorities.
TBY assists intermarried couples who display a sincere and strong commitment to live a Jewish lifestyle, in accordance with Torah and halacha.
In this situation, the Jewish spouse is becoming a fully observant Jew while the non-Jewish partner is committed to become a sincere and fully observant convert.