That’s the business’ risk for sending those prepaid envelopes out. From the USPS site itself “[Moreover, when a BRM card or envelope is misused and affixed to a sealed item, the permit holder will be responsible for payment of the applicable Retail postage and per piece fee.]
DMM 505.1.4.8, “Labels,” states that in cases when a BRM card or envelope is misused as a BRM label, USPS® treats the item as waste.
BRM cards and envelopes are designed to be mailed as a First-Class Mail card, letter, or flat only, and not as a BRM label to be attached to other items.
There is no way that those prepaid postage meant for a letter is gonna be good for 70lb.
The postal service has to have lower cost options
That’s the business’ risk for sending those prepaid envelopes out. From the USPS site itself “[Moreover, when a BRM card or envelope is misused and affixed to a sealed item, the permit holder will be responsible for payment of the applicable Retail postage and per piece fee.]
But it also says
So I’m still a but fuzzy
Weird self-deprecating thing to say, and not sure how it relates, but best wishes with that!