Becoming a professor at Madrid's Superior Institute of Religious Culture in 1929, Monreal also served as diocesan fiscal from 1935 to 1945, which was the same year he was made a doctoral canon.
Monreal became an academic at Madrid's Superior Institute of Religious Culture in 1929 and served as the financial administrator for the local diocese from 1935 to 1945, a position that coincided with his appointment as a doctoral canon that same year.