USPS Flat Rate (Domestic) Box Sizes & Prices

USPS Flat Rate (Domestic) allows merchants to ship items for a fixed price, irregardless of weight when using specific packaging.

Ensure the right rate is selected when you sign up for an Easyship account.

USPS Priority Mail Domestic Flat Rate

Package Type
Flat Rate Envelope
12 1/2" x 9 1/2"
Gift Card Flat Rate Envelope
10" x 7"
Window Flat Rate Envelope
10" x 6"  or  12 1/2" x 9 1/2"
Small Flat Rate Envelope
10" x 6"
Padded Flat Rate Envelope
12 1/2" x 9 1/2"
Legal Flat Rate Envelope
15" x 9 1/2"
Small Flat Rate Box
8 11/16" x 5 7/16" x 1 3/4"
Medium Flat Rate Box – 1 (top-loading)
11 1/4" x 8 3/4" x 6"
Medium Flat Rate Box – 2 (side-loading)
14" x 12" x 3 1/2"
Large Flat Rate Box
12 1/4" x 12 1/4" x 6"
APO/FPO/DPO Flat Rate Box
12 1/4" x 12 1/4" x 6"
Large Flat Rate Board Game Box
24 1/16" x 11 7/8" x 3 1/8"
Flat Rate Envelope (Express)
12 1/2" x 9 1/2"
Legal Flat Rate Envelope (Express)
15" x 9 1/2"
Padded Flat Rate Envelope (Express)
12 1/2" x 9 1/2"

Shipping with USPS Flat Rate (Domestic)


Based on key criteria from users and recipients, USPS Flat Rate (Domestic) has the following ratings

  • Support:
  • Tracking:
  • Speed:
  • Overall:
Market Served: Domestic
  • What is USPS Flat Rate (Domestic)?

    • 1 to 3 day shipping service provided by the U.S. Postal Service (USPS). Pricing is fixed per box size (does not consider weight) for any destination. Boxes are available in multiple sizes. All are available through the Easyship platform.
  • Pricing

    • Budget

    * Compared to other courier services available on the Easyship platform

  • Pricing Calculation

    • By volumetric weight
  • Recall Policy

    • cross-bold-red No
  • Courier Liability

    • Insurance is not offered by USPS Flat Rate (Domestic)

    *Easyship offers comprehensive insurance sold separately

  • Handover Type

    • Offers free pickup
    • No dropoff
  • Import Tax Handling

    • Only Receiver Can Pay the Taxes
  • Schedule Delivery

    • check-bold-green Offered
  • Delivery Attempts

    • Up to Two Attempts
  • Maximum Measurements

    • Height: -
    • Length: -
    • Width: -
    • Weight: 30 kg
    • Volume: -
  • Prohibited Items

    • Stand-Alone Batteries are not allowed

Common questions about USPS Flat Rate (Domestic)

  • How does USPS Flat Rate (Domestic) work?

    To create a shipment with USPS Flat Rate (Domestic), you must enter your shipment details (such as address and item details) and purchase a shipping label. Print out your shipping labels and attach to your package. The courier will collect your parcel at the pre-arranged time. From there, USPS will arrange shipment to your final destination.

    This whole process can be managed on the Easyship platform.

  • How do I track a USPS Flat Rate (Domestic) shipment?

    You can track USPS Flat Rate (Domestic) shipments using the tracking number for the shipment provided and visiting the USPS website.

  • How do I contact USPS for a shipment?

    When shipping with Easyship you do not need to contact USPS. All the information you need about your shipments is available to you through the Easyship platform. If you want to learn more about USPS you can learn more at their website or calling 1-800-275-8777.

  • What are the shipping rates for USPS Flat Rate (Domestic)?

    Pricing varies based on shipment details and destination.

    Signup today for a free Easyship account to see the most accurate rates for USPS Flat Rate (Domestic) and other services we offer.

  • How long will delivery take for a USPS Flat Rate (Domestic) shipment to United States?

    Delivery time varies on origin and destination.

    Signup for an Easyship account to see delivery time for all available couriers in your location.

  • Is there a USPS location near me?

    You can find the full list of USPS locations in United States here.

  • What can I ship with USPS Flat Rate (Domestic)?

    USPS Flat Rate (Domestic) do not have many restrictions on what you can ship, however you should be mindful that things such as alcohol, food & other items are generally restricted to most locations. With USPS Flat Rate (Domestic), stand-Alone Batteries are not allowed

  • Does USPS Flat Rate (Domestic) require a signature on delivery?

    USPS Flat Rate (Domestic) offers an optional signature on delivery service. Whether a signature on delivery will be required or not will be decided by the sender at time of shipment creation.

  • How does USPS Flat Rate (Domestic) work with Easyship?

    Easyship will detect when a shipment is eligible for a USPS Flat Rate (Domestic) shipment and show this as an option when preparing shipments. Further details on preparing shipments and obtaining the right boxes can be found here.

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