So, after going through 6 USPS priority mail flat rate envelope size choices above, it’s obvious that the Priority Mail Legal Flat Rate Envelope is the USPS’s largest flat rate envelope. What Is The Usps Largest Flat Rate Envelope? Last but not least, the Priority Mail Legal Flat Rate Envelope with 9.5 * 15 inches is the perfect choice for legal-size documents or for packages that cannot fit the five above options.

In case you want extra padding to protect your package, then it’s better to take a look at the Priority Mail Padded Flat Rate Envelope – which is 9.5 * 12.5 inches big.

There are two sizes available: 5*10 inches and 9.5*12.5 inches both have flaps closed and a see-through cover. You can put clothes in this envelope, too.So, what if you want an envelope that is as small as the Priority Mail Small but with a see-through cover for easy checking and classifying? No need to worry more USPS provides the Priority Mail Window Flat Rate Envelope for you. If your documents cannot fit the previous envelope, try the Priority Mail Flat Rate Envelope – which has a 9.5 * 12.5 inches size. It is best suited for letters, cards, or small documents. The smallest one is the Priority Mail Small Flat Rate Envelope with 6 * 10 inches (flap closed) dimensions.

There are six USPS priority mail envelope sizes available in the meantime. How Many Stamps Do I Need for a Flat Rate Package? USPS Flat Rate Envelope Sizes Available.What Can’t Go In A USPS Flat Rate Envelope?.Which Things Can Go In A USPS Flat Rate Envelope?.When Should I Use A USPS Flat Rate Envelope?.What Is The Usps Largest Flat Rate Envelope?.USPS Flat Rate Envelope Sizes Available.

Usps small flat rate envelope size