cheapest way to post a parcel to australia Cheapest way to post a parcel to Australia involves using USPS First-Class International for lightweight items under 4 lbs or USPS Priority Mail International for heavier items. Shipping consolidators like Pirate Ship or Shippo may offer discounted rates. Flat Rate Boxes can also provide cost savings for heavier parcels. Alternatives include courier services like Sendle or using third-party freight forwarders. Comparing rates, dimensions, and delivery times ensures the most economical shipping method to Australia.