Simples Nacional tax deadline moves to September 2026

Brazil is implementing significant changes to the Simples Nacional tax regime to accommodate the national Consumption Tax Reform. Under Resolution CGSN nº 186/2026, the deadline for micro and small enterprises to opt for the Simples Nacional for the 2027 fiscal year has been moved from January to September 2026. This shift aims to facilitate the transition to the new IBS (Goods and Services Tax) and CBS (Social Contribution on Goods and Services) framework.

During the September 2026 window, companies must also decide whether to pay IBS and CBS through the unified Simples Nacional payment slip or via the regular tax regime. While the decision is made in 2026, the effects will only take place on January 1, 2027. Notably, these changes do not apply to Microentrepreneurs (MEI), whose current collection rules remain unchanged for 2026.

Additionally, the regime will see the end of the cash basis (regime de caixa) for monthly tax calculations starting in 2027. Revenue recognition will shift to the accrual basis, where taxes are calculated based on total monthly gross revenue at the time of invoicing. To support this transition, the Federal Revenue Service and the CGIBS are working to strengthen the strategic role of accountants in ensuring tax compliance.