Overview

• In a Sept. 19 clarification, the Finance Ministry said moving the retention rate on interest from 0.5% to 0.9% is a legal update to a withholding scheme rather than a tax increase.
• Small savers with balances under 206,000 pesos remain exempt, and individuals earning under 400,000 pesos a year may continue to opt out of filing an annual return if not otherwise required.
• Hacienda’s example shows a saver with 500,000 pesos earning 18,950 pesos in real interest owes 4,737 pesos ISR in total, with the higher withholding reducing the amount due at filing to 237 pesos and leaving the final tax unchanged.
• Refunds or offsets are processed by the SAT and personal deductions stay in place, while opposition deputies and columnists argue the change burdens low-balance savers and could act as a de facto loss for those who do not file, especially with lower market rates expected.
• The measure remains part of the 2026 budget package pending debate and votes in the Chamber of Deputies and the Senate, and the current 0.5% rate would continue if it is not approved.