Postage Rates 2024 Large Envelopes 2024. Usps sends mail to over 180 countries, including canada and australia. The baseline postage rate to mail a flat/large envelope has increased from $1.35 to $1.39 in postage, but the price for each additional ounce also stayed the same at 24 cents per additional ounce.

Looking for a printable postage rate guide? Certified mail rate is increasing $0.45 and.