Four of North America’s biggest makers of cardboard have disclosed grand jury subpoenas from the US Department of Justice, as federal prosecutors examine whether the industry conspired to fix prices. Smurfit Westrock, International Paper, Packaging Corporation of America (PCA) and Canada’s Cascades each revealed the subpoenas in quarterly filings to the US Securities and Exchange Commission this week. The subpoenas relate to a grand jury investigation in the Northern District of Illinois into the pricing and sale of containerboard, the corrugated material used to make shipping boxes, and related products.
Smurfit Westrock said the Justice Department issued its subpoena on 22 September and that the company is “fully cooperating” with the investigation. It said it believes its business has been conducted in compliance with US antitrust laws, while warning that an adverse outcome could have a material impact on its finances. International Paper said it received its subpoena on 24 September and is cooperating, and Cascades confirmed it received one on 25 September for containerboard products sold in the United States. PCA said in its filing on Thursday that it too received a grand jury subpoena from the department’s antitrust division in September and is cooperating fully.
No charges have been brought, and the Justice Department has not accused any of the companies or their employees of a crime. A subpoena is an investigative step, not a finding of wrongdoing, and investigations of this kind do not always lead to charges. But the involvement of a grand jury is significant: packaging industry analyst Adam Josephson of Sakonnet Research noted in a memo this week that prosecutors typically have some evidence of an agreement among competitors before a grand jury is convened, and that he could find no other instance of a Justice Department price-fixing prosecution involving US containerboard producers in recent decades.
The criminal investigation runs alongside a civil class-action lawsuit, also in the Northern District of Illinois, filed in July 2025. That suit accuses a group of major containerboard producers of forming a “cartel” and colluding to raise prices from November 2020 onwards, at the expense of customers. In September, Judge Mary M. Rowland denied the defendants’ motions to dismiss the case, finding enough evidence of a potential conspiracy to warrant further exploration of the claims. The defendants filed their responses last week, several using near-identical language denying “any and all allegations of wrongdoing” and asking for the case to be dismissed. Smurfit Westrock itself was dismissed from the civil suit in October 2025, apparently because the company did not exist during the period in question — it was formed by Smurfit Kappa’s acquisition of WestRock in 2024 — though its two predecessor subsidiaries remain defendants.
The disclosures land after a year of sharp price rises. The four companies were among the major producers that introduced three rounds of containerboard price increases this year, and prices to date in 2026 are roughly 20 percent higher than a year earlier. The third wave of increases drew widespread pushback from buyers, including the Independent Packaging Association, which argued the rises were unjustified at a time of lagging demand and downgraded financial guidance from producers. Smurfit Westrock said in its filing that inflation costs this year have been “unprecedented” and are passed on to customers through price increases, though it cautioned that there is typically a three- to six-month lag before higher input costs show up in customer pricing.
The outcome of both the criminal investigation and the civil case remains uncertain, and it is too early to say whether either will lead to charges, settlements or price relief for buyers. What is clear is that the cardboard box — an unglamorous product that touches almost every online order, grocery delivery and factory shipment in the United States — is now at the centre of one of the biggest antitrust questions of the year.
Sources: Packaging Dive, “DOJ subpoenas Smurfit Westrock, IP, PCA, Cascades over containerboard pricing” (https://www.packagingdive.com/news/doj-subpoenas-smurfit-westrock-over-containerboard-pricing/873727/); Bloomberg Tax, “US Investigating Cardboard Makers Over Pricing Practices” (https://news.bloombergtax.com/antitrust/us-justice-department-probes-packaging-companies-over-box-prices); Transport Topics, “Justice Department probes packaging firms over box prices” (https://www.ttnews.com/articles/doj-probe-box-makers).
