February 5, 2019 Previous New Rate Letters (1 oz.) 50 cents 55 cents Letters additional ounces 21 cents 15 cents Outbound International Letters (1 oz.) $1.15 $1.15 Domestic Postcards 35 cents 35 cents Domestic Priority Mail Flat Rate Small Flat Rate Box $7.20 $7.90 Medium Flat Rate Box $13.65 $14.35 Large Flat Rate Box $18.90 $19.95 APO/FPO Large Flat Rate Box $17.40 $18.45 Regular Flat Rate Envelope $6.70 $7.35 Legal Flat Rate Envelope $7.00 $7.65 Padded Flat Rate Envelope $7.25 $8.00 Priority Mail Express Flat Rate Flat Rate Envelope $24.70 $25.50 Legal Flat Rate Envelope $24.90 $25.70 Padded Flat Rate Envelope $25.40 $25.70 USPS Certified Mail rates will increase to $3.50 per mailing. Return Receipt service (PS Form 3811) will increase to $2.80 per mailing. Registered Mail will increase to $12.40 and up.