After voluntarily serving for one year in the military in 1888, Heinze worked from 1898 to 1912 in the judicial service of Saxony, at the end in the position of Landgerichtsdirektor.

On account of personal contacts with Turkey, Heinze was then appointed Undersecretary of State at the Ministry of Justice of the Ottoman Empire in Constantinople.

[2] In June 1919, Heinze played a key role in making possible a compromise between the opposition and the government on the Treaty of Versailles, paving the way to its acceptance by the National Assembly.

Heinze organized supplies for the population of the Ruhr area during the occupation by French and Belgian troops.

The passive resistance against the occupiers resulted in economic collapse and hyper inflation in Germany, leading to the resignation of the Cuno cabinet in August 1923.

Heinze attempted to install a bourgeois government but was forestalled by the Saxony diet, which on 31 October elected Alfred Fellisch (SPD) as Ministerpräsident and head of a social-democratic cabinet.

In 1926/27, as the suggestion of the Turkish government, Heinze chaired the Konsularobergericht (a disciplinary court for foreign service) in Egypt.