The Postal Service filed its 2026 peak season surcharge on August 25. It runs October 4 through January 17, and it applies to Priority Mail Express, Priority Mail, Ground Advantage, and Parcel Select.
The table will be everywhere by the end of the week. The table is the easy part.
The structural thing worth knowing first
I have written before about how peak surcharges at the national carriers are built, and the important part is the second layer: a volume-based charge that scales against your own baseline from earlier in the year. You are not charged for shipping a lot. You are charged for shipping more than you usually do, measured on a lag, billed weeks after the volume moves.
USPS does not do that. No escalator, no baseline window, no measurement against your prior volume. A fixed amount per package, set by weight and zone, charged from the first parcel.
Which makes this the one peak surcharge in the market you can calculate exactly, today, without forecasting anything. Take your October through mid-January volume by weight band and zone, multiply, and you have the number. No other peak charge you carry works that way.
That should be good news. Here is why it is not quite.
What changed against last year
Commercial prices, which are the ones your invoices carry.
| Commercial, per package | 2025 | 2026 | Change |
|---|---|---|---|
| Priority and Ground Advantage, Zones 1 to 4 | |||
| 0 to 3 lb | $0.30 | $0.40 | +33% |
| 4 to 10 lb | $0.45 | $0.65 | +44% |
| 11 to 25 lb | $0.75 | $1.05 | +40% |
| 26 to 70 lb and oversized | $2.25 | $3.15 | +40% |
| Ground Advantage, Zones 5 to 9 | |||
| 0 to 3 lb | $0.35 | $0.55 | +57% |
| 4 to 10 lb | $0.75 | $1.05 | +40% |
| 11 to 25 lb | $1.25 | $1.75 | +40% |
| 26 to 70 lb and oversized | $5.50 | $7.70 | +40% |
| Priority Mail, Zones 5 to 9 | |||
| 0 to 3 lb | $0.70 | $0.85 | +21% |
| 4 to 10 lb | $1.25 | $1.75 | +40% |
| 11 to 25 lb | $2.75 | $3.85 | +40% |
| 26 to 70 lb | $6.50 | $9.10 | +40% |
| Priority Mail Express, Zones 5 to 9 | |||
| 0 to 3 lb | $1.75 | $2.35 | +34% |
| 4 to 10 lb | $3.95 | $5.55 | +41% |
| 11 to 25 lb | $7.50 | $10.50 | +40% |
| 26 to 70 lb | $13.00 | $18.20 | +40% |
Priority Mail Express in Zones 1 to 4 runs $1.40, $2.10, $4.90, and $12.55 across the same weight bands, also forty percent above last year at every tier. Parcel Select, which USPS separated out this year, runs $0.40, $0.50, $0.80, and $2.35. Large Flat Rate Boxes take $1.75 and other Flat Rate products $0.85.
Read the right column, not the dollar columns
Fourteen of the twenty-three commercial prices land on exactly forty percent. Eighteen of the twenty-three are what you get by taking last year’s price, multiplying by 1.4, and rounding to the nearest nickel.
Every price that breaks the pattern is under two dollars, which is where rounding moves a percentage a long way. Forty percent of thirty-five cents is forty-nine, and USPS prices in nickels, so it became fifty-five and reads as fifty-seven percent. That is arithmetic, not a decision about heavy parcels.
Retail behaves the same way at 1.3. The heaviest price in each grouping lands exactly there: $3.00 to $3.90, $7.00 to $9.10, $16.00 to $20.80.
So this was not a schedule rebuilt tier by tier. It reads as two decisions. Multiply commercial by 1.4, multiply retail by 1.3, round to the nearest nickel.
Commercial is the shipper side. Retail is the counter. Whatever the reasoning behind the split, the effect is that the book with contracts attached to it took an increase a third larger than the one without.
The fourth change on the same parcel
Ground Advantage Commercial has now been repriced four times on dated effective days inside one calendar year.
A 7.8 percent increase in January. An 8 percent temporary increase effective April 26. An 11.8 percent average increase on July 12, which also collapsed the sub-pound ounce tiers and moved the dimensional divisor from 166 to 139. And now a peak surcharge effective October 4.
A shipper who budgeted from the January number is three changes behind. One who budgeted from July is one behind, and the one they are missing lands in the quarter that matters.
The part USPS has not answered
The April increase was not a peak measure. It was filed in March as a transportation cost measure, nine days after diesel moved on the Iran conflict, and USPS described it as a bridge to a permanent mechanism for reflecting market conditions. In plain terms, the Postal Service is the only one of the three national carriers with no automatic fuel surcharge, so when fuel moved it had to file a price change and announce it. The other two moved a table and said nothing.
That April measure runs until January 17, 2027.
The peak surcharge announced August 25 ends January 17, 2027.
Same four products. Same terminal date. Two temporary measures running together across the entire peak window, and the release announcing the second does not mention the first.
USPS has not published how they combine. I am not going to tell you they compound, because the filing language on that point is not something I have been able to confirm, and a number I cannot source is worth nothing to you. What I can tell you is that both measures are live across the same period on the same products, and that your October cost per piece depends on an interaction the Postal Service has not explained in either announcement.
That is a question for your account team, and it is worth asking this week rather than reading the answer off an invoice in November.
What to do with the next five weeks
Calculate it, because for once you can. Volume by weight band and zone against the published prices above. This is the rare surcharge that does not require you to predict your own behavior first.
Re-baseline on invoices, not on the published increases. Four dated changes compound in ways the individual percentages do not describe, and the July divisor move means a package that was not dimensionally rated last year may be rated now.
Ask about the April measure explicitly. Not “what is our peak rate.” Ask whether the 8 percent transportation increase remains in effect during the peak window and how it is applied alongside the surcharge. Write down the answer and who gave it to you.
Check whether any of this reaches your negotiated rates. USPS said the July restructure would not affect customers on negotiated commercial rates. Whether the April measure and the peak surcharge behave the same way is a separate question with a separate answer, and it is not one to assume in either direction.
Do it before October 4. After that you are reconciling rather than planning.
Takeaway: The simplest peak surcharge in the market went up by roughly forty percent for commercial shippers and thirty for retail, and it sits on three other increases from the same year that the Postal Service has not explained how to combine. Simple to calculate is not the same as small.
When you built your Q4 shipping budget, how many of this year’s four USPS changes were in it?
