How Many Ounces Can a Letter Weigh Before There's a Need to Add Another Stamp?
The cost of a first-class stamp is $0.49, according to the United States Postal Service website as of November 2017. One needs a single stamp to mail a letter that weighs one ounce or less. Each additional ounce carries with it a cost of $0.21. This is the cost for mailing when stamps are purchased at the post office. There can be other additional charges as well, depending on the shape and size of the letter.
Cost of Postage Through Metered Mail
There is a slight discount for metered mail. The cost to mail a one-ounce letter through metered mail is $0.46, with a charge of $0.21 per additional ounce. Metered mail is mail that is sent by businesses, and it includes self-addressed stamped envelopes. A meter cannot be bought, but a company can rent one from the postal service.
Large and Oddly Shaped Envelopes
There are times when a letter may weigh an ounce or less yet will still require additional postage. The reason for this is because the envelope is not sized to fit into the sorting machines. This extra fee is called a "non-machinable letter surcharge." In order to avoid this charge, be sure that an envelope meets the postal service requirements for a standard one-ounce letter. Envelopes with clasps or raised areas that prevent them from going through the sorting machine may also require additional postage.
When a Letter Is Sent Without Enough Postage
When a letter is sent without enough postage, someone has to pay what is owed. In most cases, the post office will try to deliver the letter with a "postage due" notice. The person receiving the letter will be asked to pay the additional postage. When the person pays, they get the letter. However, if the person refuses to pay, the mail will be returned to the sender. If the sender does not include a return address on the envelope and the recipient refuses to pay, the letter becomes "dead mail." Dead mail is mail that is undeliverable, and no further attempts at delivery are made. In some cases, the mail might be returned directly to the sender, without a delivery attempt being made to the recipient beforehand.
Letter Returned for Insufficient Postage
If a letter is returned for insufficient postage, all a person has to do is add the additional postage to the envelope. The original stamp that was used is still good and can be reused on the same letter. Pay the additional postage and put it back into the mailbox. The best option is to make sure the postage is correct before sending the letter.