Pack tighter, drop a tier
Cubic tiers step every tenth of a cubic foot. Losing an inch of height on a 0.42 cu ft box can move it down a step on a long-zone shipment.
Discontinued in 2023
USPS Regional Rate Boxes and what took their place
Regional Rate Boxes A and B are gone. USPS discontinued them effective January 22, 2023 and told customers that boxes still in their inventory can still be used for shipping, but they will be processed as weight and rate packages (about.usps.com, checked 2026-07-28). The shipment they suited, small and dense and not travelling far, now belongs to cubic pricing or to plain weight-based Ground Advantage.
Discontinuation citedCubic tiers publishedDMM 223 conditions
The job outlived the box
Short-zone heavy parcels still need a pricing route. It just is not a branded carton any more.
What USPS said, and when
The service ended by notice rather than by fading away. Two sentences from the USPS bulletin item cover the whole change, read at about.usps.com on 2026-07-28.
- Effective January 22, 2023 (and subject to approval by the Postal Regulatory Commission), the boxes were discontinued and their pricing no longer applied.
- Customers with Priority Mail Regional Rate Boxes A and B in their inventory can still use them for shipping, but they will be processed as weight and rate packages.
So a Regional Rate Box left on a shelf is now just a box. It carries a parcel perfectly well and it is priced like any other parcel of that size and weight going that distance.
What made the boxes worth hunting for was the zone-sensitive fixed price: cheap on short hops with heavy contents, which is exactly the parcel that weight-based pricing punishes hardest. That gap did not close when the boxes went, it moved.
Cubic pricing does the same job
The nearest surviving answer is cubic, a commercial Ground Advantage structure priced on the volume of the box in tenths of a cubic foot. It rewards exactly what a Regional Rate Box rewarded: a small carton with heavy contents in it.
| Tier | Zone 1 | Zone 2 | Zone 8 |
|---|---|---|---|
| 0.10 cu ft | $7.45 | $7.51 | $10.13 |
| 0.20 cu ft | $7.82 | $7.89 | $11.84 |
| 0.30 cu ft | $8.39 | $8.45 | $14.67 |
| 0.40 cu ft | $9.07 | $9.13 | $17.29 |
| 0.50 cu ft | $9.59 | $9.66 | $18.90 |
DMM 223 sets the conditions and they are tight: 0.50 cubic foot or less, 20 pounds or less, and no side longer than 22 inches. Measurements round down to the nearest quarter inch, volume comes from length times width times height divided by 1728, and a soft pack is measured as length plus width with a combined cap of 36 inches.
Twenty pounds is the ceiling, which lands cubic in much the same territory the regional boxes occupied. Above it, the parcel goes back onto the weight grid.
A worked example
Take an ordinary 12 x 10 x 6 in carton. Multiply the sides and you get 720 cubic inches; divide by 1728 and it is 0.42 cubic foot, which sits in the 0.50 tier. Its longest dimension is 12 inches, comfortably inside the 22 inch limit, and at 5 lb it is well under the 20 pound cap. That box clears every condition.
Box used: 12 x 10 x 6 in at 5 lb. Volume by the DMM 223 formula: 12 x 10 x 6 = 720 cubic inches, divided by 1728 = 0.42 cubic foot. Longest side 12 in. Weight 5 lb.
For scale rather than comparison, the same carton quoted $13.52 as the cheapest live rate from Newark, NJ 07102 to Atlanta, GA 30303 on 2026-07-28 through our checkout. That is a different measurement from the published cubic tier and is printed here only to show the order of magnitude a real parcel lands at.
If the contents are heavier than 20 lb or the carton is longer than 22 inches, cubic is out and the ordinary weight grid applies. Our cubic pricing guide works through the measuring rules in more detail.
The old boxes still ship things
There is no rule against using one, and USPS said as much. Just price the shipment before you assume it is a bargain.
Heavy and near is the awkward case
That was the regional sweet spot and it is now split between cubic and the ordinary grid. Quote both rather than guessing which applies.
Regional Rate Boxes, answered
Are USPS Regional Rate Boxes still available?
No. USPS discontinued Priority Mail Regional Rate Boxes A and B effective January 22, 2023, stating that boxes left in customer inventory can still be used for shipping but will be processed as weight and rate packages.
What replaced Regional Rate Boxes?
Nothing was issued as a direct swap. The nearest equivalent for a small dense parcel is commercial cubic pricing under USPS Ground Advantage, which prices on the volume of the box rather than the pounds inside it.
What qualifies for cubic pricing?
USPS requires each cubic mailpiece to measure 0.50 cubic foot or less and weigh 20 pounds or less, with the longest dimension no more than 22 inches, rounding each measurement down to the nearest quarter inch. Volume is length times width times height divided by 1728.
Can I still use the old boxes?
USPS said inventory can still be used for shipping and will be processed as weight and rate packages, so the price now follows the scale and the zone like any other parcel. The regional price that made them worth using is what went away.