Yes. They are authentic USPS issued postage. All of our postage undergoes a series of tests for authenticity, and is money-back guaranteed to our customers. All fraudulent and counterfeit items we receive are reported to the United States Postal Inspectors Office. We have aided law enforcement in several fraudulent and counterfeit postage cases over the past years, and have direct access to an inspector agent representative specializing in such cases.
Beware of counterfeit postage stamps being sold on eBay, Amazon, and other websites. Especially if the discount is very large. Nobody can purchase stamps from USPS at a discount, so if they are selling them for less than face value it is almost certainly likely they are counterfeit. Buying and selling counterfeit postage stamps is a Federal crime.
We are able to sell new stamps at a discount because we purchase them from companies going out of business, leftover marketing campaigns, stamp collectors, and even the general public, such as leftover wedding or graduation mailers. Which is why you see postage stamps of all different types, conditions and eras on our website.