The inflation update factor for a home sold in November 2026

In short

When a resident sells a home in Mexico, the documented cost is updated for inflation before the gain is computed (Income Tax Law, art. 124). For a sale in November 2026, the update factor is 3.1747 for a purchase in June 2000, 2.0066 for a purchase in June 2010, 1.6796 for a purchase in June 2015, 1.3759 for a purchase in June 2020: MX$1,000,000 paid in June 2010 counts as MX$2,006,600 before the other rules apply. Payotte computes the factor for every month since 1990 from INEGI's consumer price index, with the method of the Federal Tax Code (art. 17-A).

Factor for a sale in November 2026, by month of purchase

Factor truncated to four decimal places (the Federal Tax Code asks for calculations to the ten-thousandth). Purchases from September 2026 onwards give a factor of 1 for this sale month. The notary computes the factor on the actual dates of your deeds.

How Payotte computed it

Article 124 of the Income Tax Law (LISR) updates the cost "for the period from the month of acquisition to the month immediately before the sale". Article 17-A of the Federal Tax Code (CFF) divides the INPC of the month before the most recent month of that period by the INPC of the month before the oldest month, uses the last published index when the one needed is not yet out, and sets the factor at 1 when the result is below 1. The INPC series is INEGI's general index, base second half of July 2018 = 100.

Questions

How is the update factor calculated?

It is the consumer price index (INPC) of the month before the last month of the period, divided by the INPC of the month before the purchase month. The period runs from the purchase month to the month before the sale. For a sale in November 2026, the numerator is the INPC of September 2026: 146.075.

Can the factor be less than 1?

No. The Federal Tax Code sets it at 1 when the division gives less than 1.

Is the whole purchase price updated this way?

Not directly. Article 124 first separates the land from the building (20% land if the deed does not split them), reduces the building part by 3% a year, never below 20% of its initial cost, and then updates both with this factor. The updated cost can never be less than 10% of the sale amount for real estate.