The usefulness of accounting information for the design, planning and execution of the national budgeting process depends on a number of factors, such as the horizontal and vertical organization of government bodies, the structure of the state administration, adequate and timely reporting of relevant data, data interpretation and analytics. This paper focuses on the analysis of the role and application of accounting and budgeting information in Slovenia, as well as reporting in the national budgeting process. Structured interviews with prominent experts in the field were used as the main data collection technique. The results reveal the limited usefulness of the information offered by the accounting system for budgeting purposes and several collateral findings. These findings could be used as a starting point in the reform of Slovenian public financial management, as well as in similar countries. The findings of this Slovenian study will be of importance to regulators, reformers and officials in other, similar, countries that are transitioning from cash-based accounting to accrual accounting and consequently redesigning their public sector accounting and budgeting systems. The paper reveals factors that should be reconsidered before reforming the public sector accounting and budgeting systems, such as having sound political support and the commitment of all stakeholders, as well as public and professional supervision at the later stages.