The exchange rate (FIX) is determined by Banco de Mexico as an average of quotes in the wholesale foreign exchange market for operations payable in 48 hours. Banco de México informs the FIX from 12 o'clock onwards each banking day. It is published in the Official Gazette (Diario Oficial de la Federación) one banking business day after its determination date, and is used to settle liabilities denominated in U.S. dollars payable in Mexico on the day after its publication in the Official Gazette. To obtain more information regarding this exchange rate see: The Third Title, Chapter V of the regulation3/2012 from Banco de México (Available only in Spanish)..
As of November 1, 2021, Banco de México modified the methodology for calculating the "Closing" exchange rate, publishing the "Mexican peso closing exchange rate" from that date. For more information on this exchange rate refer to: Methodological Note: DETERMINACIÓN DEL TIPO DE CAMBIO DE CIERRE DE JORNADA
Source: Banco de México.