If you are having to crush the items in and squeeze the end over, it is probably too tight for those items. To explain in more detail, the first point means that the packet must be sealable without stressing the envelope. Tape cannot be used to hold the envelope shut.You should be able to easily close the provided envelope with the items that you have put inside it.There are a few rules for using these envelopes, as follow: What Are The Priority Mail Flat Envelope Rules? We will tell you all about this type of mailing and answer a few of the most common questions.

Tape cannot be used to hold the envelope shut. The basic rule is that whatever you are shipping must fit into the given envelopes, without those envelopes being modified in any way. In order to utilize the USPS Priority Mail Flat Rate service, it is important to follow their rules.

Mail service has become quite advanced in recent years introducing a variety of different packaging options, including the flat rate envelope one. We all need to mail one thing or another from time to time.

Priority mail flat rate envelope rules