After graduating from Uppsala University in 1907, Moding joined the Swedish Ministry for Foreign Affairs.

He passed mogenhetsexamen at Nya Elementarskolan in Stockholm on 15 May 1901 and enrolled at Uppsala University the same year.

[2] He was extra rapporteur in the Ministry of Finance from 1914 to 1915 and a member of the State Trade Commission in 1915 as well as vice CEO of Sydsvenska kreditaktiebolaget in 1916 and vice CEO and board member of the Nordiska Kompaniet from 1916 to 1922.

He was Sweden's representative at the diplomatic conference on the suspension of import and export bans in Geneva from 1927 to 1928 and chairman of the board of the merchant navy pension institution (Handelsflottans pensionsanstalt).

[2] Modig was State Secretary and Director-General for Administrative Affairs in the Ministry of Commerce and Industry from 1926 to 1930.