Such a ruling would result in a refund of billions of dollars to US-based companies, who overpaid duties on imported products. It is expected that major firms such as Walmart will receive refunds worth millions of dollars.

According to CBP, over 330,000 importers have paid around $166 billion in duties on over 53 million shipments. Up to April 14, 2018, 56,497 importers have registered with the agency’s online payments system, qualifying them for refunds worth $127 billion plus interest.

It is required that companies provide detailed information regarding the nature of imported products subject to customs duties. If the application is genuine, a refund is issued within 60 to 90 days.

However, not all cases will initially be included. In the first phase, only cases where tariffs were estimated but final accounting has not been completed, or claims with a deadline within 80 days of final accounting, will be processed.

Legal experts have urged companies to exercise caution when applying. Expert Meghan Supino said that even a single entry in a file is incorrect or ineligible, the entire claim or a relevant portion could be rejected.

She also noted that technical difficulties may arise in the initial days of the system's launch, so companies should exercise patience.

Expert Nghi Huynh said that companies must maintain records of each application, as a single file can contain thousands of entries, and a small mistake can lead to a claim being rejected.

On February 20, the US Supreme Court ruled 6-3 that the Trump administration had overstepped its bounds by imposing tariffs under the Emergency Powers Act of 1977. The US Court of International Trade later ruled that affected companies should receive refunds.

Small businesses are also preparing for refunds. Brad Jackson, co-founder of Minnesota-based After Action Cigars, said his company paid $34,000 in tariffs last year and is now preparing documents. However, he expressed concern that if refunds take several months to arrive, it will not immediately resolve the cash crunch.

Refunds will go directly to companies, but will not necessarily benefit ordinary consumers. Many companies passed on the burden of tariffs to customers by raising prices, and they are not required to refund those funds now.

However, delivery companies like FedEx and UPS, which in some cases directly charged customers, are preparing to issue refunds.

CBP has stated that payments will be made in phases after claims are investigated. This process is seen as a major initial step toward providing financial relief to businesses affected by the tariffs.