In 1710, Van der Heim began his career as secretary of the Generaliteitsrekenkamer (Financial audit institution).
In 1727, he succeeded Simon van Slingelandt, who had been appointed Grand Pensionary of Holland, as Treasurer-General of the Union.
However, the pensioners of Haarlem and Dordrecht, Visscher (described as pro-English by the French ambassador de Fénelon) and Teresteijn van Halewijn (no support in his own city) dropped out.
Eventually, both parties came to an agreement with a compromise text and Van der Heim accepted the position.
An important issue during the term of office of Grand Pensionary Van der Heim was the inability of the Regents to reform the state finances and reduce fraud in tax collection.
The introduction of a very progressive income tax in Holland in 1742 during Van der Heim's term of office, namely the Personeele Quotisatie, and unique in Europe, was supposed to provide financial relief.