After working at the Amsterdam office of the Twentsche Bank (a precursor of ABN AMRO), he opened a small accountancy practice in 1917 in his home on the Viottastraat in Amsterdam. Amsterdam was a bustling trade and investment hub for European and Asian industrialists.
He worked at the Amsterdam branch of Twentsche Bank (a predecessor to ABN AMRO), which led him to open a small accounting firm in 1917 from his home on Viottastraat in Amsterdam. As a significant commercial center, Amsterdam drew in European and Asian industrialists.