Some people have been noting issue when mailing with the new USPS Flat Rate Materials. All of the prices for flat rate can be found in my previous blog. This is a quick reference directly from the USPS Website. You can take this to your post office if needed for clarification. The main issues that are floating around is that you may not add tape to your Flat Rate Packages. This simply is not true.
Here is the wording directly from the USPS Website:
When sealing a Flat Rate Box or Flat Rate Envelope, the container flaps must be able to close within the normal folds. Tape may be applied to the flaps and seams to reinforce the container; provided the design of the container is not enlarged by opening the sides and the container is not reconstructed in any way.
Flat Rate — Quick Reference
Available for Domestic and International
EXPRESS MAIL
Flat Rate Envelope
12-1/2" x 9-1/2"
Legal Flat Rate Envelope
15" x 9-1/2"
PRIORITY MAIL
Flat Rate Envelope
12-1/2" x 9-1/2"
Legal Flat Rate Envelope
15" x 9-1/2"
Padded Flat Rate Envelope
12-1/2" x 9-1/2"
Gift Card Flat Rate Envelope
10" x 7"
Small Flat Rate Envelope
10" x 6"
Window Flat Rate Envelope
10" x 5"
Small Flat Rate Box
8-5/8" x 5-3/8" x 1-5/8"
Medium Flat Rate Boxes
13-5/8" x 11-7/8" x 3-3/8"
11" x 8-1/2" x 5-1/2"
Large Flat Rate Box
12" x 12" x 5-1/2"
APO/FPO/DPO
Large Flat Rate Box
12" x 12" x 5-1/2"
Large Video Box (Flat Rate pricing for international only)
9-1/4" x 6-1/4" x 2"
DVD Box (Flat Rate pricing for international only)
7-9/16" x 5-7/16" x 1-3/8
Note: Flat Rate prices are available when material is sent in a USPS-produced Flat Rate Envelope or Box. When sealing a Flat Rate Box or Flat Rate Envelope, the container flaps must be able to close within the normal folds. Tape may be applied to the flaps and seams to reinforce the container; provided the design of the container is not enlarged by opening the sides and the container is not reconstructed in any way.
Weight restrictions for domestic Express Mail and Priority Mail Flat Rate Envelopes and Boxes are 70 pounds.
Weight restrictions for Priority Mail International are 4 pounds for the Flat Rate Envelopes, Small Flat Rate Box, and DVD Box and Large Video Box; 20 pounds for the Medium Flat Rate Boxes and the Large Flat Rate Box.
Weight restrictions for Express Mail Flat Rate International vary by country and are noted in the Individual Country Listings. However, the maximum weight limit for any Express Mail International shipment is 70 pounds.
You may order free packaging supplies at usps.com/shop and find out more information about Priority Mail at prioritymail.com.
You can find this reference HERE
Really useful visual reference, even without much text, that USPS flat-rate chart simplifies choosing the right envelope or box. Flat-rate shipping is a game-changer: one price, regardless of weight (up to 70 lbs), and fast Priority delivery across the U.S.
ReplyDeleteAt Mail Pros USA, we often help businesses choose the perfect flat-rate options—especially for dense or heavy items, to streamline direct mail campaigns and keep costs predictable. Using the right size flat-rate packaging saves time and money, and ensures packages still fit mailboxes or retail drop-offs securely.
Great overview of USPS Flat Rate options! Just to note: as of 2025, typical Flat Rate postage runs approximately $11.00 per envelope at retail, with Commercial Rates lowering that to about $9.70. Large Flat Rate Boxes are about $29.95 retail.
ReplyDeleteAlso worth mentioning: USPS is instituting temporary holiday surcharges this year—adding around $0.90 to Flat Rate Envelopes and $1.45 to Large Flat Rate Boxes from early October to mid-January.
At Laguna Digital, we’re always mindful of these shifts when budgeting for direct mail campaigns—Flat Rate remains a great value, but planning ahead for seasonal increases helps us keep costs predictable and ensure on-time delivery.