Banks incurred significant losses as a result of military actions in the Second World War. Some authorities of credit institutions were evacuated, files and property were destroyed, financial assets, especially securities of the Polish state, were lost or lost their value. Debt collection was impossible in most cases. Bank Polski (Bank of Poland), a central institution, as a result of its evacuation was unable to fulfil its main tasks, including money issuance. As a result, payments to customers were significantly limited or even suspended. Already in the first months of occupation access of the Jewish community to bank loans was significantly limited.

The banking policy in the Generalgouvernement was subordinated to general economic objectives set by the highest Reich authorities. In the initial phase of occupation the Germans planned to destroy the economy of the Generalgouvernement in order to make it dependent on the Reich. In the area of banking, this meant pressure on liquidating credit institutions. These plans concerned not only institutions regarded by the Nazis as Jewish but also to state-owned banks, which played a dominant role in the pre-war Polish banking.

This policy started to be eased gradually already in November 1939. This was a result of two factors: the fiasco of peace talks, which could have resulted in establishing a "residual" Polish state, and the desire to exploit the Generalgouvernement economy as a supplement of the Reich economy. The effect of the swing in economic policy in the area of banking was the gradual opening of banks and using them for funding the occupant's activities. It was necessary to legally address problems resulting from military actions. First of all, a new central bank, the Issuing Bank in Poland, was established and from April 1940 it began the issuance of new occupation money. Also, the Office of Banking Supervision was established, the issue of pre-war deposits began to be regulated (payments to customers regarding their pre-war deposits had to be obtained from the liquidated assets of the pre-war credit institutions) as well as matters regarding interest on deposits.

The change of plans regarding the future of the Generalgouvernement in 1942 - from a country inhabited by Poles and Jews it was to become a German province - caused a change in banking policy. The Reich authorities insisted on allowing a greater involvement of German banks which would occur as a result of a takeover of Polish banks by the largest Reich banks. Both the Generalgouvernement officials and authorities of some German institutions, strongly but unofficially opposed such plans. Finally, developments on the military front put an end to these plans in 1943.

As the Eastern front approached the borders of the Generalgouvernement, the economy was being destabilised. The economy was burdened to an ever greater extent by payments to the Reich. As a result of German rulings, banks were forced to significantly limit their funding of branches of industry which did not produce for army and trade. There was evidence of panic amongst some deposit holders. The Warsaw Uprising was a huge blow to banking in the Generalgouvernement. It resulted in a paralysis of the head office activities of the majority of credit institutions, bank files and property were either looted or destroyed.

Between July 1944 and January 1945 the German administration no longer attempted to pursue an economic policy, being busy with preparations for the evacuation of the German government and institutions.