The free boxes and envelopes on the USPS website are quite popular with shippers looking to keep packaging costs low. However, did you know that USPS lets you alter their Priority Mail Flat Rate packaging to ship weight-based Priority Mail? It’s one of the Postal Service’s best-kept secrets that not too many everyday shippers know about…but it’s a real thing, and we’re here to tell you more about it!
Table of Contents
- Where Can I Get Flat Rate Boxes or Envelopes?
- You Need to Pay for Flat Rate Postage If You Want to Use Flat Rate Boxes (Most of the Time)
- It’s Perfectly Fine to Change Flat Rate Packaging to Ship Weight-Based Priority Mail
- What If My Post Office Doesn’t Accept My Package?
Where Can I Get Flat Rate Boxes or Envelopes?
First thing’s first: if you’re in the market for some USPS flat rate boxes or envelopes, you can pick them up for free at your local Post Office. You can also order them on the Postal Service’s website, if you don’t feel like making the trek (hey, we don’t blame you).
You Need to Pay for Flat Rate Postage If You Want to Use Flat Rate Boxes (Most of the Time)
In the majority of cases, USPS is very strict about paying for the exact shipping service that’s marked on your box or envelope. For example, if you have a Priority Mail Medium Flat Rate Box, that’s the service you need to pay for. You won’t be able to ship regularly Priority Mail, Priority Mail Express, or Parcel Select Ground in that box.
The same goes for Priority Mail Express flat-rate envelopes! If you put something in a Priority Mail Express flat rate envelope and try to ship it First Class Package, guess what? USPS will charge you for Priority Mail flat rate postage.
For more information, check out our guide on paying for the service marked on your USPS-branded boxes or envelopes.
It’s Perfectly Fine to Change Flat Rate Packaging to Ship Weight-Based Priority Mail
Contrary to popular belief, you can technically alter your flat rate packaging to qualify for weight-based rates. Typically, it’s crucial that you pay for the specific service marked on your USPS box or envelope. Most postal workers will tell you that if you use flat rate packaging, USPS will charge you for the corresponding flat rate service. While this is true in 99% of cases, this one particular situation is the exception. In case you don’t believe us, check out the following direct quote from the USPS domestic mail manual:
“If [a Flat Rate Envelope] or [Flat Rate Box] is presented at the office of mailing and the customer has manipulated or reconstructed it, the container is accepted using weight and zone — not the Flat Rate price.”
In layman’s terms, that means you can ship weight-based Priority Mail instead of whatever flat rate service is marked on your box or envelope. However, the only way USPS lets you do this is if you alter the packaging in some regard! That means you can cut it down to a different size or change the shape (if you want to)…but, if you present a flat rate box or envelope without any changes, USPS will make you pay for that specific flat rate service.
What If My Post Office Doesn’t Accept My Package?
If your Post Office doesn’t accept your package, then you should present proof, or ask to speak to the Postmaster. A great place to start would be to pull up a copy of the domestic mail manual that we’ve linked above.
The key here is that flat rate envelopes must seal with the self-adhesive in order for them to truly be flat rate. Once you change it by expanding it and taping it up, USPS no longer considers them to be flat rate. So, if you change your flat rate packaging in a similar way that the picture above shows, USPS should only accept the package at weight-based rates.