Revenue Mobilization Trust Fund (RM-TF) is a response to the Addis Ababa Action Agenda, the Addis Tax Initiative and the 20130 Agenda for sustainable development. To increase their capacity for domestic resource mobilization, the developing countries have a critical need for aid to improve their fiscal capacity. RM-TF is therefore focused on supporting capacity development to strengthen fiscal policy and administration in a select group of low and lower middle-income countries. RM-TF will have two main areas of focus:-Support for capacity-building for the implementation of reforms. This will involve supporting the reforms that recipient countries need to make in their tax systems, including transforming fiscal frameworks and strengthen the administrations. The program is based on the long-term commitment of the authorities of the countries within the framework of a well sequenced support from RM-TF and other providers of technical assistance. This is carried out, among other things, with the help of investments by short-and long-term experts for direct support at the ground level. -Targeted support for reforms. This work will focus on specific areas of the tax system where improvement is most needed. Targeted support can be designed within the framework of a multiannual broader commitment but can also be used in countries where the need is more focused to a specific area, and where a more extensive reform programme is not required or if a country has lower absorption.Other important components of RM-TF contain:-a special training module which will focus on physical and online courses to support and complement the capacity-building efforts in selected areas of tax policy and administration, especially for countries with low capacities. -Diagnostic tools will play a key role in defining the priority reforms and subsequent capacity-building. In particular, the Tax Administration Diagnostic Assessment Tool (TADAT), the Revenue Administration-Fiscal Information Tool (RA-FIT), and the Revenue Administration-Gap Analysis Program (RA-GAP) will be used to assess where the impact of technical assistance is likely to be greatest, as well as to monitor the progress of the reforms. -Applied the analytical work that examines developments linked to the revenue reforms in developing countries, will provide support to both technical assistance and educational streams. The research will aim at assessing emerging issues, trends and methods in tax policy and administration.