Postage rates will go up and average of 1.9% on Sunday, January 21st. As in past rate increases, those mailings flats and parcels will see a larger increase than those mailing letters. The First-class 1 ounce letter stamp will cost $0.50, an increase of a penny. The meter rate for a 1 ounce letter will also goes up a penny to $0.47. If you have questions about this rate increase, please contact us.