There were so many agencies operating in Washington during World War II that the WRB’s mandate was clearly going to overlap with a few of them. UNRRA worked with refugees, the Intergovernmental Committee on Refugees was supposed to formulate plans for relief and rescue, and the War Relief Control Board supervised private relief work. It was easy to work out an agreement with UNRRA (their director, Gov. Herbert Lehman, was related to Henry Morgenthau by marriage). It took until April to work out an agreement with the IGC (which was based in London and fundamentally far more conservative than the WRB). The WRB needed just a simple memo of understanding for the War Relief Control Board.
The WRCB supervised the National War Fund, an enormous fundraising operation, and dispensed relief money to private agencies. In exchange, the private agencies would not fundraise separately. After the WRB was created, agencies registered with the WRCB still had to comply with those regulations, but the two agencies agreed to collaborate. The WRCB sought WRB approval before dispensing money having to do with refugees.