The United States Postal Service and carriers like UPS and FedEx all have varying requirements, and may offer special rates for frequent shippers.
For more details, contact your carrier:
- For USPS: 1-800-275-8777
- For UPS: 1-800-742-5877
- For UPS International: 1-800-782-7892
- For FedEx: 1-800-463-3339
UPDATED: April 25, 2022