2025-06-062025-06-062025-04-17ALMEIDA, R. H. O. Reforma tributária brasileira e seus impactos na carga tributária das micro e pequenas empresas . 2025. 83 f. Dissertação (Mestrado em Ciências Contábeis) - Faculdade de Administração, Ciências Contábeis e Ciências Econômicas, Universidade Federal de Goiás, Goiânia, 2025.http://repositorio.bc.ufg.br/tede/handle/tede/14404This study investigated the impacts of the Tax Reform (LC No. 214/2025) on micro and small enterprises (MSEs) opting for the Simples Nacional regime, focusing on the adoption of the dual Value Added Tax (VAT) model. The main objective was to assess changes in the tax burden, effects on formalization, and compliance challenges. The study was divided into two parts: the first part of quantitative and qualitative nature, adopted a mixed approach, combining a multiple case study with quantitative simulations of tax scenarios for six micro and small enterprises (two in commerce, two in services, and two in industry) to evaluate variations in the tax burden with the CBS and IBS levied outside the Simples Nacional. The second part of the study of a qualitative nature, involved a thematic content analysis of public interviews and legislative debates, using MAXQDA software for coding and interpreting expert perceptions on the reform and its implications for tax evasion. The results revealed that the taxation of CBS and IBS outside Simples Nacional led to significant increases in the tax burden, especially in the commerce sector (+116.76% to +206.98%) and services sector (+186.53%), while the industrial sector experienced a smaller impact (+6.78%), possibly due to the use of tax credits. Furthermore, 50% of the participating companies indicated a risk of migrating to informality, and 83.33% were unaware of available tax incentives. The qualitative analysis reinforced that, despite the intention of simplification, the reform still faces structural challenges and may lead to an increase in tax evasion if compensatory measures are not adopted. Based on these findings, it is recommended to implement sector-specific policies with differentiated rates, fiscal education programs for MSEs, and a review of the legislation to allow the use of tax credits within Simples Nacional. The main limitations of the study include the restricted sample and reliance on projections based on fixed rates, as well as the use of secondary sources (interviews and published debates), which may introduce bias. For future research, it is suggested to expand the geographical/sectoral scope, conduct a longitudinal analysis of the tax transition (2026-2033), and compare it with other tax regimes to assess long-term impacts. It is concluded that, while tax reform represents progress in modernizing the system, its success will depend on adjustments that ensure equity and proper support for MSEs, preventing an increase in informality and ensuring the sustainability of these businesses under the new tax regime.Acesso Abertohttp://creativecommons.org/licenses/by-nc-nd/4.0/Reforma tributáriaSimples nacionalMPEsCarga tributáriaEvasão fiscalTax reformMSEsTax burdenTax evasionCIENCIAS SOCIAIS APLICADAS::ADMINISTRACAO::CIENCIAS CONTABEISDissertação