In mid-January 2026, multiple major outlets reported that President Donald Trump announced a 25% tariff targeting any country that “does business” with Iran, described as effective immediately via a social media statement.

For supply chain leaders, the headline isn’t just “a new tariff.” It’s the uncertainty: Which countries qualify? What counts as “doing business”? Will CBP publish implementation guidance? Will it stack on top of existing tariffs? details and legal authority were not clearly explained at announcement, which creates real execution risk for importers planning near-term arrivals.

Who could be exposed (based on reported Iran trade ties)

Even before you get to policy mechanics, the exposure mapping is straightforward: any sourcing country that trades with Iran could be in scope if the tariff is implemented as described.

Iran’s notable ties with countries including:

• China (reported as Iran’s largest trading partner)

• India (bilateral trade at $1.34B over the first 10 months of 2025)

• Turkey ($2.3B exports to Iran in 2025; imports $2.2B over 11 months)

• Additional examples include Germany, South Korea, and Japan with varying degrees of trade activity.

For logistics teams, the takeaway is simple: this isn’t limited to direct Iran trade lanes (which are already heavily restricted). It potentially impacts your normal origin countries, depending on how “doing business” is defined.

The two big unknowns that can break your cost model

1) What does “doing business with Iran” mean in practice?

That phrase can be interpreted broadly (any trade) or narrowly (specific sectors, sanctioned goods, energy, etc.). Without a defined threshold, importers may not know:

• whether a small volume of trade qualifies,

• whether indirect trade through intermediaries qualifies,

• whether subsidiaries/affiliates count,

• whether services/financial flows count (vs physical goods).

2) How (and when) would CBP actually collect it?

To be enforceable at entry, CBP typically needs implementing instructions—e.g., how the tariff is assessed (HTS “9903” provisions), how it is declared, and what documentation is required.

What this means for shippers: the operational risks

Even if nothing changes overnight, the risk is in the transition window:

• Landed cost volatility: A sudden 25% adder can turn a profitable SKU into a margin loss—especially for high-volume, low-margin categories.

• Entry delays: If CBP guidance requires additional declarations or proofs, brokers may need new data from suppliers before filing.

• Sourcing disruption: If a key origin country is implicated and the tariff sticks, sourcing and finance teams may push rapid re-routing or re-sourcing decisions.

• Contract friction: Purchase agreements may not specify who owns “new tariffs,” which triggers disputes between buyers, sellers, and customers.

What GLC can do to help

If your team is moving freight into the U.S. and you’re worried about sudden tariff application, you need two things: clean entry execution and real-time guidance as rules change.

GLC supports importers with customs brokerage + freight forwarding coordination so you can make decisions quickly when policy shifts hit the dock.

If you want, share to [email protected]:

• your top origins,

• ETA/arrival window, and

• the commodities/SKU families most exposed,

…and we can help you pressure-test documentation readiness and contingency routing.