Mexico’s Law on Acquisitions, Leases and Services of the Public Sector, published in a new form on April 16, 2025, sets fixed prices as the rule. Article 65 allows “decrementos o incrementos a los precios” (decreases or increases in prices) under an agreed adjustment formula. When prices rise or fall generally, government agencies “deberán reconocer incrementos o requerir reducciones” (must recognize increases or require reductions).

Article 74 allows contracts in force to be increased, as long as the changes do not exceed “en conjunto, el veinte por ciento” (altogether, twenty percent) of the original amount or quantity. Under Article 77, instead of rescinding a contract, an agency may give the supplier “otro plazo, que le permita subsanar el incumplimiento” (another deadline, which allows the supplier to correct the breach).

Article 66 of Mexico’s Federal Tax Code states that the tax authorities, at the taxpayer’s request, may authorize “el pago a plazos” (payment over time). The payment can be deferred for up to twelve months, or paid in installments over up to thirty-six months.