Does Mexican Customs' Data Explain Nearshoring Better Than US Trade Data?

Oddly, Mexican Customs’ data - not U.S. trade data - offers the most granular view of how global supply chains are nearshoring to service the United States. The majority of trade between the U.S. and Mexico occurs under Mexico’s IMMEX program. In a nutshell, Mexico’s IMMEX program provides favorable tax and tariff treatment of imported inventories. Those imported inventories must be transformed with value added and exported from Mexico. Asia and the rest of the world (“ROW”) have driven IMMEX in a big way.

Mexico also operates a second innovative customs program: virtual trade. With virtual imports and exports, IMMEX operators can utilize domestic Mexican fabricators to add value.

Perhaps Asian and ROW companies are using USMCA to ensure tariff-free access to the U.S. Or maybe IMMEX is simply more profitable for those companies. Nevertheless, Mexican Customs’ data between 2020 and 2024 shows the footprint of global supply chains prior to the 2024 presidential election and subsequent changes in U.S. trade policy.

Proportion of Mexican Exports to U.S.: IMMEX vs Definitive — **Figure 1:** IMMEX dominated Mexican exports to the U.S. between 2020 and 2024. The proportion of IMMEX trade remained at almost identical levels. The trade in USD grew from $267B to $415B for a CAGR of 12%. **Note: Definitive** implies that the import is consumed within Mexico.

Proportion of IMMEX sourcing in dollars by regions of the world — **Figure 2:** IMMEX operators source the largest portion of their parts and material from Asia and the rest of the world (ROW). In turn, the Asian and ROW content of IMMEX exports to the U.S. is almost 4X the USMCA content.

Value of virtual imports vs IMMEX import values by region of the world — **Figure 3:** USMCA IMMEX content dominates the virtual trade. The value added by Mexican fabricators was 94% of value in 2020 and exceeded 100% in 2024. Asian IMMEX suppliers also began to utilize virtual trade more in 2024. In 2024, the ROW use of virtual trade was negligible.

IMMEX in Mexican Customs’ Data

The Mexican government holds IMMEX companies to a strict standard on how inventory is staged and transformed. An IMMEX company only maintains the favorable tax and tariff treatment on imported parts and materials if those parts and materials are exported with value added. In other words, an IMMEX company doesn’t claim the favorable treatment if the imported materials or parts are used commercially within Mexico.

Mexican Customs tracks the IMMEX program on behalf of the Mexican government. IMMEX operators must designate a line item on a customs clearance as “IMMEX”. (The pedimento is the name of the Mexican customs clearance.) Each “IMMEX” line item on an import pedimento must roll up to an “IMMEX” export pedimento. A line item almost equates to a separate ten-digit harmonized code.

Virtual Shipments Within the IMMEX Program

Another feature of Mexico’s IMMEX program requires some “customs” lingo. IMMEX allows operators to utilize “virtual imports and exports.” For example, an operator imports material cleared as IMMEX but wants to use a separate Mexican fabricator to add value to the material. The IMMEX operator can move the material to the Mexican fabricator under a “virtual export.” Likewise, the Mexican fabricator can receive the material as a “virtual import.” From Mexican Customs’ perspective, the IMMEX operator never needs to move cargo out of bond.