What is “Flat Rate” Shipping?
For one rate flat rate, you can send a package weighing up to 70lbs anywhere in the continental US through the United State Postal Service. Priority Mail® Flat Rate Shipping is one of the most widely used services at the USPS. Shipments sent using the Priority Mail flat rate service arrive within 1-3 business days – this also conveniently includes Saturdays!
Below you’ll find a flat rate pricing chart that compares flat rate pricing to standard shipping prices. We’ve also outlined the difference between Retail and Commercial Base pricing.
Retail Pricing – Amount charged at the Post Office counter.
Commercial Base Pricing (CBP) – Discounted pricing available to recurrent Priority Mail customers that frequently use specific postage payment methods. You can get CBP using shipping software.
Flat Rate Types and 2020 Rates
| Type | Size | Retail | Commercial | Difference |
| Flat Rate Envelope | 12 ½ x 9 ½ | $7.75 | $7.15 | $0.60 |
| Legal Flat Rate Envelope | 15 x 19 ½ | $8.05 | $7.45 | $0.60 |
| Padded Flat Rate Envelope | 12 ½ x 9 ½ | $8.40 | $7.75 | $0.65 |
| Small Flat Rate Box | 8 5/8 x 5 3/8 x 1 5/8 | $8.30 | $7.65 | $0.65 |
| Medium Flat Rate Boxes | 11 x 8 ½ x 5 ½ ,
13 5/8 x 11 7/8 x 3 3/8 |
$15.05 | $13.20 | $1.85 |
| Large Flat Rate Boxes | 12 x 12 x 5 ½,
23 11/16 x 11 ¾ x 3 |
$21.10 | $18.30 | $2.80 |
| ADO/FPO/DPO Large Box | 12 x 12 x 5 ½ | $19.60 | $16.80 | $2.80 |
How to Send Packages with Priority Mail Flat Rate
- Pick up Priority mail flat rate boxes from your local Post Office or order them on the USPS website. Pro Tip: THEY’RE FREE!
- Prepare your packages and ship from the Post Office, or, with easy-to-use shipping software, ship right from your office. USPS will pick them up free of charge, no matter how many packages you’re sending!
- Track your package to its final destination using your shipping software
- Breathe easy!
“If It Fits, It Ships”
Seems too good to be true? The only catch here is that your items need to fit into the flat rate packages without any significant bulging or tearing. And remember, it can’t be more than 70lbs.
Rundown of Benefits – What’s Not to Love?
- Priority Mail includes up to 50% insurance on most packages
- The heavier the package, the bigger the savings!
- With shipping software, Priority Mail offers advanced USPS tracking
- Priory Mail arrives in 1-3 days, including Saturdays!
- Priority Mail boxes and envelopes are FREE! And so are pickups from your office
- Need overnight delivery? Try Priority Mail Express
