For the standardization of radiation processing dosimetry on an international scale, and for further promotion of dosimetry as quality control measures in high-dose applied research and irradiation industry, the International Dose Assurance Service (IDAS) has been initiated in the framework of the high-dose standardization programme. IDAS is being provided on the basis of an Agreement between IAEA and its Member States. As a transfer standard the GSF-operated ESR/alanine dosimeter has been used for the service. The significance of IDAS and the major achievements made to date are discussed.