A price increase letter lands on a Tuesday. Elevated feedstocks, tightening supply, margin recovery, effective the first of the month. You've read this one before, pretty much word for word. Two more just like it from other suppliers are sitting right underneath it.
So you log the number, and maybe you forward it to finance. Somewhere in the back of your head, it's already booked as a done deal. Right?
Well, not so fast. That letter is a resin price increase nomination, meaning a producer is telling the whole market what it'd like to get, weeks before anyone knows what it'll actually get. The number that ends up on your invoice comes out of a separate process entirely.
So how far apart do the two get? In April 2026, PlasticsToday reported a polyethylene nomination of $0.30 a pound, with the market expected to realize about half of that. That's fifteen cents per pound between the ask and the expected outcome, on the same resin in the same month. On five million pounds a year, it's the difference between a manageable plastic resin price increase and $750,000 you didn't plan for.
Start with the letter itself. A resin price nomination is a producer saying it intends to raise contract prices on a grade by a set amount, starting on a set date. It goes out to every customer at once and to the trade press too, so you'll sometimes see the number in a market report before your own buyer's even replied.
And producers file these constantly. The big polyethylene sellers keep one in the queue more or less year-round, so when a hurricane forms or a cracker trips offline, the ask is already sitting there. That rhythm is easy to miss from the buying side, but it's one of the reasons resin prices move the way they do. So when an announced resin price increase shows up in your inbox, it doesn't mean anything changed last week.
The nomination only tells you what a producer wants. Nobody knows yet what the market will give them, which is the number you'll end up paying.
Once the ask goes out, the next few weeks decide whether it holds. Most of what happens in those weeks sits outside the producer's control. Four things usually do the deciding:
Take April's polyethylene nomination, where producers asked for $0.30 a pound and PlasticsToday's resin price report expected about half of that to stick. That's still a lot of money to hand a resin supplier over a form letter. And the first day or two after it lands is when you have the most say, which is why a fast reply backed by data moves the number more reliably than anything you try at renewal.
Even the timing isn't what the letter says, because resin price increase implementation runs on its own calendar. The producer prints an effective date at the top, the day it wants the increase to start. An index-linked contract, though, moves when the resin contract settlement publishes, usually after that date.
So the letter doesn't tell you when you'll pay. A busy month of nominations doesn't tell you much about supply either, which cuts against a reflex a lot of buyers have. Six letters in a month feels like evidence that the market must be turning.
It usually isn't that simple. Increases can land across most of the major resin families in the same few weeks while the underlying picture points the other direction entirely. Producers might be sitting on an inventory build, with new capacity coming into the market and feedstock contracts settling lower instead of higher. Demand may never have quite shown up.
None of that stops the letters from going out, because producers file nominations on their own schedule rather than in response to the month's fundamentals. That's just producer discipline, but from the buying side it looks a lot like scarcity, since the letters read the same either way.
That doesn't make the cost pressure imaginary, though. Feedstocks move, outages happen, and plenty of increases are at least partly justified on cost. Pretending otherwise just makes you the buyer nobody takes seriously. The trouble is that the letters all look alike, so counting them tells you nothing about which ones have genuine cost behind them and which don't. You find that out when the index settles, which is weeks after you needed to know.
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You can't tell from a letter whether it'll hold, but you can track how your suppliers' nominations have played out. Your own realization rate, supplier by supplier, is sitting in data you already have.
The mechanics are boring, which is the good news here. For every nomination, log the date, grade, amount asked, and effective date. When the month closes, write down what your contract price did. Two or three cycles in, you've got a resin price realization rate for each supplier. A year in, you've got an actual record of whether a particular seller runs hot, instead of a hunch.
A few things usually fall out of that record:
But your own record only tells you what happened to you. It can't tell you whether $0.15 a pound was a good result, because that depends on where the wider market settled. ResinSmart benchmarks draw on more than 3 billion pounds of transaction data, so you can see how your number compares with everyone else's.
So a resin price increase letter is just an opening position. The price you pay gets settled over the weeks that follow, so buyers who treat the two as the same number end up paying the difference.
ResinSmart gives resin procurement teams live benchmarks plus feedstock and spot data, with hands-on negotiation support included in the same subscription. That way, the next time a letter lands, you'll already know what the number should be before you answer it.
Start your free trial and see how your last few settled prices compare with what buyers like you paid.
A resin price increase nomination is a producer's announcement that it intends to raise contract prices on a given resin grade by a stated amount from a stated date. It's a proposal filed ahead of the settlement period, not a settled price. Major producers file them as a standing pricing practice rather than only in response to a market event.
A nominated resin price increase is the amount a producer announces, while the realized increase is the amount that settles into contract pricing. The two are frequently far apart, and the distance between them gets decided during the settlement period rather than when the letter goes out. Buyers who log both numbers can see how wide that spread usually runs for each supplier.
How much of a resin price increase nomination gets implemented varies by resin, by month, and by supply conditions, so no fixed percentage holds across the market. Inventory levels, feedstock direction, demand, and the volume of buyer pushback all move the settled number. A buyer's own realization rate, tracked across several cycles, is the more useful figure.
A nominated resin price increase reaches a buyer's invoice once the relevant settlement publishes and the supplier applies it, which usually trails the effective date printed in the letter. An index-linked contract adjusts on the settlement rather than the announcement. For most monthly-settled grades, you'll be billed the new price after the date printed in the letter, not on it.
Resin producers do file price increase nominations when supply is long. Nominations go out ahead of settlement as a standing pricing practice, so they can appear across several resin families at once even while inventories build and feedstock costs fall. Nomination activity reflects producer pricing strategy, so it's a poor read on actual scarcity.
Resin buyers can track nominations against what they actually paid by logging every nomination with its date, grade, amount, and effective date, then recording the settled contract price beside it once the month closes. Two or three cycles produce a realization rate per supplier. Set that rate against independent market benchmarks and you can see whether the outcome was competitive or simply accepted.