
When sending a flat envelope, each Forever First-Class Mail stamp covers enough postage for one ounce. How Many Stamps Do I Need for Flat Envelopes? If you’d like to track your envelope the same way you can track a package, then you’ll need to purchase Certified Mail service at your local Post Office. Something to keep in mind is that regular First-Class Mail service doesn’t include any kind of tracking, whatsoever. USPS technically makes more money from their mail products than their shipping products, so the workers at your local Post Office won’t hesitate to classify a thin envelope as something that needs to be sent via the mail, rather than with one of the USPS shipping services. Therefore, you’ll need to send these out using good old-fashioned stamps for First-Class Mail. USPS requires you to mail flats instead of ship them, since they’re too thin to be considered actual packages. If your mailer is less than 3/4 inches think, then you’ve got what USPS calls a “flat” envelope.

What Do I Do if My Mailer isn’t 3/4 of an Inch? Pro Tip: If you’re on the hunt for some cool bubble mailers, ULINE has the best selection we’ve come across. One of the most popular ways to ship bubble mailers like these is USPS First Class Package Service. As long as the total thickness of your mailer is at least 3/4 of an inch, you’ll be able to use any of the USPS shipping services to send it. This applies not when the bubble mailer is empty, but when the contents of your shipment are inside.

USPS will only accept bubble mailers as packages if their total thickness is 3/4 of an inch or more.

What Do I Do if My Mailer isn’t 3/4 of an Inch?.Bubble Mailers and Envelopes are Considered Packages When They’re 3/4 Inches Thick or More.Bubble mailers are one of the most popular envelopes for sending products…but did you know that USPS may not technically consider bubble mailers as packages if they aren’t thick enough? Table of Contents When it’s time to send out products, you’ve typically got two choices for packaging: boxes, or envelopes.
