The Asian Development Bank would lend $250 million to the country to help stem revenue losses through corruption.
The loan would support "anti-corruption revenue programs" launched by the government’s Bureau of Internal Revenue (BIR), the Philippine government’s main tax collection agency, the ADB said.
It said the money would help the country gain higher investment flows by improving fiscal management, reducing corruption and scaling up social safety net programs.
The program "is designed to support the country’s key development efforts at a time of a significant global economic downturn," said ADB senior economist Kelly Bird.
Japan will provide between $100 million and $150 million of the funding.
Global corruption monitor Transparency International last year listed the Philippines as being the 39th most corrupt country in the world.