Containerboard Prices Rose Again in September 2026: What Packaging Buyers Should Do Now

On September 18, 2026, Fastmarkets RISI recognized a $70 per ton increase in linerboard and a $100 per ton increase in recycled corrugating medium, effective with September 1 pricing. It is the third round of North American containerboard increases in 2026, driven mainly by permanent mill closures that have tightened supply. Buyers of corrugated boxes and partitions should expect higher costs to follow and should act now on spec, sourcing and inventory strategy rather than simply absorbing the increase.

What exactly changed in September 2026?

Containerboard producers announced aggressive increases for September, ranging from $80 to $140 per ton, with Packaging Corporation of America announcing $140 per ton. In its mid-September report, Fastmarkets RISI partially recognized those announcements:

• Linerboard: up $70 per ton.

• Recycled corrugating medium: up $100 per ton.

• Coated recycled paperboard (CRB): flat, despite producers seeking $50 to $60 per ton.

• Solid bleached sulfate (SBS): flat, despite a similar attempted increase.

Other major producers, including International Paper, Smurfit Westrock, Pratt and Cascades, have typically followed earlier 2026 waves with matching or proportional announcements, which builds industry-wide momentum before the Fastmarkets RISI index recognizes an increase.

Because linerboard and medium are the raw materials for corrugated boxes, partitions and pads, this is the move that matters most for industrial packaging buyers. The flat boxboard grades affect folding cartons more than shipping packaging.

Why are containerboard prices rising when box demand is soft?

Supply, not demand, is driving this cycle. Roughly 3.9 million tons of US containerboard capacity has been permanently removed through mill closures. With less capacity in the market, producers have been able to push increases through even though overall box demand has been relatively subdued.

How will this affect what I pay for corrugated packaging?

Box and partition pricing typically follows containerboard pricing, often with a lag as converters work through contracts and existing board inventory. With three increases already this year, many buyers are seeing cumulative cost pressure on every corrugated line item, and the effect is largest on high-volume, heavy-board items. For background on the broader cost drivers, see our earlier guide on corrugated price increases.

What can packaging buyers do to offset the increase?

The most effective responses are structural changes to how packaging is specified and bought, not one-time negotiations:

• Audit usage and specs: review each item for over-packaging, oversized boxes and board grades heavier than the product actually needs.

• Engineer lighter alternatives: custom corrugated configurations can replace bulky bubble wrap or foam-in-place, cutting material spend and volumetric footprint.

• Consolidate spend: bringing corrugated, pallets, foam and supplies to fewer suppliers increases volume leverage.

• Stock strategically: managed inventory buffers and vendor managed inventory cushion your operation against sudden market moves and keep lines running.

Should I lock in pricing or wait?

With mills removing capacity rather than adding it, waiting for prices to fall back is a risky plan. Buyers with steady volume are usually better served by reviewing specs now, consolidating volume, and agreeing on pricing structures and inventory programs with a supplier that controls part of its own supply chain.

Who helps Michigan manufacturers manage rising corrugated costs?

All Packaging Solutions (Allpacks), headquartered in Flint, Michigan, is a vertically integrated manufacturer and distributor of industrial packaging. We review customer usage to find over-packaging and inefficient grades, engineer lighter corrugated alternatives, and hold managed inventory to cushion price swings. See our corrugated solutions and inventory programs, or request a quote for a review of your current packaging spend.

Frequently asked questions

How much did containerboard prices increase in September 2026?

Fastmarkets RISI recognized a $70 per ton increase in linerboard and a $100 per ton increase in recycled corrugating medium in its September 18, 2026 report, effective with September 1 pricing.

Why are containerboard prices going up in 2026?

The main driver is reduced supply. Roughly 3.9 million tons of US containerboard capacity has been permanently closed, allowing producers to raise prices even with relatively soft box demand.

How can I reduce the impact of corrugated price increases?

Audit packaging specs for over-packaging, switch to lighter engineered corrugated designs where possible, consolidate packaging spend for volume leverage, and use managed inventory programs to stabilize pricing.