Automated Postal Center - Merrimack 510 Daniel Webster Hwy Merrimack, NH 03054 Phone : (603) 424-9405 Business Category Automated Postal Centers Toll-Free           (800) ASK-USPS Fax           (603) 424-2672 Post Office - Merrimack 510 Daniel Webster Hwy Merrimack, NH 03054 Phone : (603) 424-9405 Post Office - Merrimack Business Category Post Offices Toll-Free           (800) ASK-USPS Fax           (603) 424-2672