This might be called the "Costco effect." Late last month, warehouse retailer Costco Wholesale filed a lawsuit against the Trump administration, seeking a courtdeclaration that the tariffs imposed under the International Emergency Economic Powers Act of 1977 are illegal, and requesting a "full refund" of the tariffs it has paid.

Since then, Doreen M. Edelman, a partner at Lowenstein Sandler and chair of its global trade and national security practice, has received calls daily from companies eager to know whether they should also file lawsuits to obtain, or at least preserve, their right to refunds of paid tariffs.

"The Costco case has made many companies nervous," Edelman said in an interview on Monday. She added that businesses are essentially considering whether to take similar legal action while awaiting a Supreme Court ruling on the legality of the sweeping tariffs imposed by President Trump this year.

Last month,Supreme Court justices questioned both sides in the historic consolidated cases—Learning Resources Inc. et al. v. Trump and V.O.S. Selections Inc. et al. v. Trump. According to Supply Chain Dive, a sister publication of CFO Dive, the plaintiffs represent more than a dozen states and small businesses, claiming they will suffer severe economic losses if Trump's so-called "reciprocal tariffs" are upheld.

A ruling in that case could provide more clarity, but for now, Edelman said Costco-style lawsuits are just one of several strategies companies can pursue to seek tariff refunds. In an interview with CFO Dive, Edelman analyzed the current state of legal and procedural issues that could affect companies' ability to protect their rights to tariff refunds.

The following Q&A has been edited for clarity and brevity.

CFO Dive: What should companies and chief financial officers know about potential tariff refunds?

Doreen M. Edelman:Let's take a step back. Suppose the Supreme Court rules these tariffs are illegal... Then the question is: how will the court handle refunds? Typically, they will instruct the lower court. So, if the case is remanded to the Court of International Trade, that court also has several options, one of which is to tell U.S. Customs and Border Protection (CBP), which collects the tariffs, to figure out how to implement it. They've been through this before and have unilaterally announced they would refund all tariffs and provided a process. But in this case, we certainly know the Trump administration won't be happy to refund these billions of dollars.

CFO Dive: Why did Costco file its lawsuit?

Doreen M. Edelman:They paid early in the process, and they were concerned that if the Supreme Court doesn't rule until next spring, they might not have enough time to submit all the paperwork to meet protest deadlines. That's one reason. Another is that Costco has a significant amount of money at stake for refunds, involving a lot of paperwork and many entry filings... So it makes perfect sense for Costco to file suit, and it's not afraid of the government. It knows it has an extremely loyal customer base and won't be harmed by this, and might even gain a reputational boost from filing, so all factors led Costco to bring this lawsuit.

CFO Dive: It's interesting that Costco's lawsuit seems very urgent.

Doreen M. Edelman:That's exactly what scares many people. They tried to extend the liquidation time point, which is a key issue. Their request was denied, so their position is more precarious. Now, other companies have also tried to extend liquidation dates, and there have been successful cases.

CFO Dive: What advice do you have for companies considering whether to file a lawsuit?

Doreen M. Edelman:The first thing I tell companies is, we need to know when your goods were liquidated. Contact your customs broker or research it yourself, tell me when your goods were liquidated, and then we can discuss the options... where they want to spend their money, and whether they're willing to spend more and file court documents?

In most cases, waiting a bit is reasonable. If your goods aren't liquidated until early next year, there's no rush. Let's see what the Supreme Court says. If we get some indication that the Supreme Court doesn't know how to handle it and remands the case to the Court of International Trade, and that court says we'll review it but won't expedite... then companies can decide: "Is this too slow for us? Will we go bankrupt by then... Do we need other options?" One approach might be to file a lawsuit directly or join an existing one.

CFO Dive: What is liquidation?

Doreen M. Edelman:Nominally, it's 314 days after import. It's somewhat like a final reconciliation of the price.

CFO Dive: Besides litigation, what existing procedures do companies currently have to obtain tariff refunds?

Doreen M. Edelman:Within a certain number of days after filing the entry, you can make a "post-entry amendment," saying: "I made a mistake, I paid this much in tariffs, but now these tariffs are illegal, so I should have only paid this much." But this procedure is not yet mature, so set that aside for now. Another option is to request CBP to extend our payment deadline... that is, the liquidation date. If it can be extended, once the Supreme Court rules, we can adjust the paperwork and obtain a refund through the protest system, which is a third option, provided your goods haven't been liquidated or you haven't completed the tariff settlement for all entry filings.

For many of my clients... we haven't yet reached the typical 300-day liquidation date, so there's plenty of time, because once liquidation occurs, you have 180 days to file a protest, which is the traditional way to request a refund.

CFO Dive: What are your expectations for the timing of the Supreme Court's ruling in this case?

Doreen M. Edelman:Some say it could be in December. I'm skeptical of that, because this is a major decision, and every justice might want to express an opinion, and they have to decide who writes the opinion. Add in the holiday factor, and I think the ruling will come in the spring.