The National Trust Ecofund was established in 1995 through the mechanism of transforming part of Bulgaria's debt into environmental protection projects - the Debt-for-Environment swap - an agreement between the governments of the Swiss Confederation and the Republic of Bulgaria.

Over the 30 years of its operation, the National Trust Ecofund has financed 515 projects of municipal authorities, schools, universities, companies, institutes of the Bulgarian Academy of Sciences, non-governmental organizations, etc., located in more than 150 municipalities. The overall amount of the supported projects is more than 135 million EUR and the amount of the NTEF grant contribution is more than 60 million EUR. The average percentage of the grant funding is about 46% (min. 19%, max. 85%).

Over the years, the National Trust Ecofund has often been a pioneer, implementing initiatives for the first time without the option of relying on established models. This has consistently required creativity grounded in sound knowledge and reliable information. The management of NTEF-funded projects involves a lower administrative burden than other programmes, and beneficiaries are regarded as partners of the Fund.