How to Respond to a Resin Price Increase Letter

“We are writing to inform you that effective [date], pricing for [grades] will increase by [X]¢/lb.”

Every resin buyer knows this letter. Most treat it as an announcement. But it’s not. It’s a proposal, and proposals get evaluated. Or at least they’re supposed to.

What you do in the first 48 hours after receiving it determines whether you absorb the full increase, negotiate it down, or reject it entirely.

Step 1: Validate the Resin Price Increase Before Responding

The first instinct is to either accept or panic. But both are wrong. Before you do anything else, check the fundamentals:

• Feedstock costs. Has ethylene or propylene actually moved enough to justify the stated increase? If your PE supplier wants 5¢ but ethylene moved 2¢, the math doesn’t add up.
• Spot market. If spot is flat or declining, the increase lacks market support. The spot-contract delta is one of the fastest ways to gauge whether an increase reflects reality.
• Timing and trigger. Is this tied to a real event—an outage, feedstock spike, or trade disruption? Or is it a scheduled margin-enhancing attempt? PE producers nominate increases as insurance. They file early and often, knowing not all will stick.
• Supply conditions. Check operating rates and inventory levels. If producers are running below 85% with healthy inventories, the supply picture doesn’t support an urgent increase.

Taken together, these checks help you separate cost-push increases (feedstock-driven, often at least partially justified) from margin-enhancing increases (strategic, usually negotiable). That distinction shapes everything that comes next.

Step 2: Respond to the Supplier With Data

Once you’ve validated the market picture, it’s time to respond. Don’t absorb silently, but don’t make it adversarial either. Frame it as alignment.

Start by asking for specific cost justification. What feedstock cost changes drove the request? What production costs shifted? How did they arrive at the magnitude? This “anti-form-letter” approach puts the burden of proof where it belongs—on the supplier. Industry data suggests roughly 80% of form-letter price increases can’t be fully justified when suppliers are asked to document the cost drivers. Many shrink or disappear entirely when met with an informed response.

Even partial pushback changes the math. Getting a 5¢ increase down to 2¢ on 10 million pounds saves $300,000. That’s well worth an email.

Speed matters here, too. Respond within 48 hours. A delayed response signals acceptance. However, a fast, data-backed response signals that the increase will be scrutinized. Suppliers calibrate their expectations based on how quickly and how specifically you push back.

And when it comes to tone, “Help us understand the drivers so we can work together on timing and magnitude” lands far better than “We reject this.” You want the supplier to see you as informed and reasonable, not combative.

Step 3: Build a Pattern That Creates Long-Term Resin Pricing Leverage

One pushback is a negotiation. Consistent pushback, though, builds a reputation.

Suppliers mentally categorize their accounts. Some buyers accept everything. Some push back on everything. And some push back with data. That last group gets the best treatment over time.

So, document every increase, your response, and the outcome. Track your supplier’s historical behavior along the way. Do they always lead with 5¢ and settle at 2–3¢? Do they apply increases faster than decreases? Over time, that record becomes its own form of leverage.

It’s also worth sharing your market data openly with the supplier. Counterintuitively, showing them you track feedstocks and spot prices doesn’t damage the relationship. It actually signals sophistication. Believe it or not, many suppliers prefer doing business with buyers who understand the market, because conversations are more productive when both sides are working from reality rather than positioning.

The Next Resin Price Increase Letter Is Already Being Drafted

Ultimately, the only variable is how you respond. Buyers who validate, respond with data, and track outcomes build compounding advantage. And each negotiation gets easier because the precedent is set and the data is already there.

ResinSmart gives procurement teams the real-time feedstock, spot, and supplier pricing intelligence to evaluate every increase letter the moment it arrives. Schedule a demo today and see what informed pushback looks like