When you’re shipping products that require the use of large envelopes, it’s common for questions to comes up around charges due to size. As a service to your customers, it's important to make sure you’re informed about any possible extra fees or restrictions.
A lot of USPS mail is subject to certain surcharges known as nonmachinable surcharges. These surcharges apply only when a letter cannot be automatically processed. USPS uses machines to automatically sort their letters and envelopes. If it can’t sort them because of too much thickness or an odd bulge you will be charged. Since the USPS large envelopes have their own price structure, the nonmachinable surcharge won’t affect you.
First class mail larger than letter size:
Many people think if a First Class envelope is larger than letter-size that it will have to be over 1/4 inch thick to be priced as a large envelope. However, the 1/4 inch thickness is a guideline for maximum thickness of letters and envelopes. Learn more about letter sizes with ShippingEasy's USPS size guide.
Typically, if your letter exceeds any of the measurement sizes for a letter it will be counted and priced as a large envelope. If it weighs more than, or exceeds the large envelope sizes it may be subject to further price change.
If you’re shipping your flat rate envelopes you don’t have to worry about balloon rates or USPS dimensional weight since they work off a different price structure. Learn more about flat rate envelopes.