Free USPS Priority Mail Boxes To Become Smaller

The USPS has announced they will be reducing the size of some free Priority Mail boxes and envelopes. Two Priority Mail envelopes and six Priority Mail boxes will be getting smaller, with the reductions ranging from 1/8″ smaller in length on the Priority Mail Tyvek envelope to 2 1/2″ smaller in width on the Priority Mail Regional Rate Box B.
The USPS states these changes are being made to help process Priority Mail boxes and envelopes more efficiently on their sorting equipment, reducing the need for manual package sortation.
Priority Mail Box Size Changes
Item | Service | USPS Store SKU | OLD Outside Dimensions | NEW Outside Dimensions | Summary of Change |
---|---|---|---|---|---|
Envelope | Priority Mail Tyvek Envelope | EP14 | 11-5/8” (W) x 15-1/8” (L) | 11-5/8” (W) x 15” (L) | Length of envelope is getting smaller by 1/8" |
Envelope | Priority Mail APO/FPO Tyvek Envelope (Mili-Pac) | MILIPAC | 11-5/8” (W) x 15-1/8” (L) | 11-5/8” (W) x 15” (L) | Length of envelope is getting smaller by 1/8" |
Box | Priority Mail Large Flat Rate Box | LFRB | 6” (H) x 12-1/4” (W) x 12-1/4” (L) | 6” (H) x 12” (W) x 12-1/4” (L) | Width of box is getting 1/4" smaller |
Box | Priority Mail APO/FPO Large Flat Rate Box | MILIFRB | 6” (H) x 12-1/4” (W) x 12-1/4” (L) | 6” (H) x 12” (W) x 12-1/4” (L) | Width of box is getting 1/4" smaller |
Box | Priority Mail | 0-1092 Box | 2-7/8” (H) x 12-1/4” (W) x 13-11/16” (L) | 2-7/8” (H) x 12” (W) x 13-11/16” (L) | Width of box is getting 1/4" smaller |
Box | Priority Mail | 0-1095 Box | 3-1/8” (H) x 12-1/2” (W) x 15-5/8” (L) | 3-1/8” (H) x 12’ (W) x 15” (L) | Width of box is getting 1/2" smaller, length getting 5/8" smaler |
Box | Priority Mail Regional Rate Box B | RRB-B2 | 3” (H) x 14-1/2” (W) x 16-1/4” (L) | 3” (H) x 12” (W) x 15” (L) | Width of box is getting 2 1/2" smaller, length is getting 1 1/4" smaler |
Box | Priority Mail | Box 7 | 8-1/2” (H) x 12-1/4” (W) x 12-1/4” (L) | 8-1/2” (H) x 12” (W) x12-1/4” (L) | Width of box is getting 1/4" smaller |
Online retailers who have extra stock of the older box sizes will still be able to use the USPS free shipping supplies until their boxes and envelopes are exhausted. The new box sizes started shipping from the USPS.com site in late September 2021.