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US tariff uncertainty is becoming a permanent supply chain challenge

August 19, 2026

US importers face another period of significant trade policy change as the Trump administration expands its use of tariffs across countries, commodities and industries.

The immediate challenge is understanding which measures apply and how they interact. The wider issue is more fundamental: Section 301 is developing into a broad mechanism for imposing additional tariffs, while stricter customs enforcement increases the financial consequences of getting classification, valuation or origin wrong.

For importers, tariff exposure can no longer be treated as a temporary disruption. It increasingly needs to form part of sourcing, landed-cost and customs compliance decisions.

New tariffs broaden importer exposure

The latest changes follow the expiry of temporary Section 122 tariffs introduced in February 2026 after the Supreme Court overturned the administration’s earlier use of emergency powers for its ‘Liberation Day’ tariffs.

On 24 July, the administration introduced new tariffs on 59 countries and the European Union following a Section 301 investigation into goods allegedly produced using forced labour. The measures effectively restored a 10%–12% minimum tariff across economies responsible for around 99% of US imports, although significant product exemptions remain.

The UK was placed in the 10% group rather than the 12.5% tier applied to many other countries. There are product-specific exemptions under the UK-US Economic Prosperity Deal, so the 10% does not apply universally.

UK automotive exports benefit from a 10% tariff within the agreed 100,000-vehicle quota, aerospace goods have preferential treatment, and UK pharmaceutical exports secured 0% tariffs in April 2026. Different Section 232 or other measures can also apply depending on the commodity.

These duties can also stack on top of existing measures, helping push the estimated overall US effective tariff rate to approximately 10.8%.

Some individual measures go considerably further. Selected Brazilian goods face additional tariffs of 25%, while certain Canadian products have been targeted with duties of 50%. From 31 July, some pharmaceutical imports also became subject to tariffs reaching 100%.

More measures could follow. An investigation into excess industrial capacity covers 16 economies, including China, India, Japan and the EU, while further action targeting digital policies and specific industries remains possible.

The near-term outlook therefore points towards continued volatility rather than simplification. Importers should expect tariffs to change by country, product and policy objective, making total landed-cost calculations increasingly important when comparing suppliers and sourcing locations.

Enforcement raises the cost of getting customs wrong

Tariffs are only one part of the financial exposure. US Customs and Border Protection is also moving towards more aggressive enforcement.

Importers face increased scrutiny of the three areas fundamental to duty assessment: tariff classification, customs valuation and country of origin. Errors can result not only in additional duty assessments but potentially penalties where authorities believe tariffs have been avoided.

The scope for mitigating penalties may also be narrowing. Industry analysis indicates that reductions which historically could reach 90% are becoming less readily available, with mitigation potentially limited to around 50% for trusted traders able to demonstrate effective written controls and robust compliance procedures.

This makes customs governance increasingly important. Importers should review classifications, origin determinations and valuation methodologies before goods arrive rather than relying on retrospective corrections.

Procurement contracts also deserve attention. Businesses may need clearer provisions determining which party absorbs new tariffs and what happens if government action materially changes the economics of an existing sourcing agreement.

Tariffs are likely to remain part of the landscape

Legal challenges continue, including action involving 25 US states, but importers should be cautious about building their strategy around the prospect of tariffs disappearing.

Section 301 has expanded well beyond its previous association with China and is increasingly being used across different countries and policy objectives. Further investigations are expected, suggesting additional tariff announcements remain possible.

Even successful legal challenges may not deliver lasting certainty if the administration replaces overturned measures using alternative statutory authority.

For importers, this changes the emphasis from reacting to individual tariff announcements to building greater resilience into customs and sourcing strategies. That means modelling landed costs under different tariff scenarios, reviewing alternative origins and suppliers, maintaining accurate customs data and identifying opportunities to use legitimate duty-management mechanisms.

Metro’s growing US footprint combined with customs brokerage capability at every US gateway, gives importers the support they need as tariff and enforcement requirements become more complex. Our teams can review classification, valuation, origin and duty exposure before cargo moves, identify potential customs risks and help you understand how changing tariffs affect your true landed cost.

With US trade policy changing quickly, don’t wait for a new tariff or customs intervention to expose a problem. Talk to Metro now about reviewing your imports, customs compliance and duty exposure. EMAIL Managing Director Andrew Smith.