The United States Postal Service offers flat rate boxes and envelopes that may help online stores reduce shipping costs while improving a shopper’s buying experience.
Shipping can be a significant challenge for ecommerce merchants. A business must pay shipping charges and carrier fees, buy packing materials, and pay labor to pick and pack each order. Moreover, for much of the industry, free and fast ecommerce delivery is the norm. Shoppers expect to place an order, get free shipping, and have that order in about two days. You might call this expectation the Amazon Prime effect.
Fortunately, the USPS has been a pioneer in flat rate shipping services. The postal service’s first flat rate offering began in February 1991 when the Priority Mail flat-rate envelope was introduced.
More than a decade later on November 20, 2004, the USPS released the first Priority Mail flat rate box. Today, USPS flat rate services address many ecommerce delivery problems and costs.
Advantages of Flat Rate Shipping
Among the various carriers available to North American online merchants, the USPS offers some of the most attractive options, especially with its aforementioned flat rate and prepaid flat rate boxes and envelopes.
Here are seven reasons to consider these services.
- Free boxes. USPS flat rate boxes are free. Merchants can simply order them at no cost and start shipping. Merchants will still need to purchase packing peanuts or similar cushioning material, but not having to pay as much as $1 per box can be huge savings.
- Known costs. Although shipping calculators are accurate, there are times when the actual shipping cost for a package exceeds what the merchant expected. Flat rate boxes have a known cost — no surprises.
- Priority delivery. The USPS flat rate boxes are Priority Mail, meaning that a package will normally be delivered in two or three days. Priority Mail packages also get special handling in the USPS system.
- No surcharges. The USPS does not add fuel, residential, or Saturday delivery surcharges to any shipment.
- More addresses. The USPS delivers to every U.S. address, including post office boxes and government addresses like APO (Army/Air Force Post Office), FPO (Fleet Post Office, for Navy), and DPO (Diplomatic Post Office, for U.S. embassies). Other U.S. carriers can only reach these addresses when the postal service delivers that last mile.
- Security. Only the USPS is authorized to place packages in mailboxes. Plus, unlike some carriers that simply leave packages on the porch, the USPS will try to re-deliver large packages in some cases. Not abandoning packages may help prevent purchase fraud or theft.
- Law enforcement protection. Flat rate USPS shipments are protected by U.S. federal law enforcement, which, again, may contribute to less fraud and theft.
USPS Flat Rate Shipping Prices
The USPS offers several flat rate shipping options, including a variety of envelopes and boxes. Each flat rate envelope or box includes three pricing tiers. The “at the post office” rate is what a very low volume shipper would pay. Nearly any ecommerce business would be able to obtain the “commercial base” rate, and high volume ecommerce shippers would enjoy the “commercial plus” rates.
I collected the rates shown below on May 20, 2018 from the USPS’s rate sheets available under the downloads tab on the USPS pricing page.
| Flat Rate Service | Dimensions | At the Post Office | Commercial Base | Commercial Plus |
|---|---|---|---|---|
| Flat Rate Envelope | 12 1/2″ x 9 1/2″ | $6.70 | $6.55 | $6.35 |
| Padded Flat Rate Envelope | 12 1/2″ x 9 1/2″ | $7.25 | $7.10 | $6.90 |
| Legal Flat Rate Envelope | 9 1/2″ x 15″ | $7.00 | $6.85 | $6.65 |
| Small Flat Rate Box | 8 11/16″ x 5 7/16″ x 1 3/4″ | $7.20 | $7.05 | $6.85 |
| Top-loading Medium Flat Rate Box | 11 1/4″ x 8 3/4″ x 6″ | $13.65 | $12.85 | $12.45 |
| Side-loading Medium Flat Rate Box | 14″ x 12″ x 3 1/2″ | $13.65 | $12.85 | $12.45 |
| Large Flat Rate Box | 12 1/4″ x 12 1/4″ x 6″ | $18.90 | $17.65 | $17.10 |
| APO/FPO Large Box | 12 1/4″ x 12 1/4″ x 6″ | $17.40 | $16.15 | $15.60 |
USPS Rates Compared to Other Carriers
With the USPS flat rate boxes, “if it fits, it ships” (up to 70 pounds), making the service especially good for dense, heavy products that are also relatively small in size.
Below are several price comparisons, looking at USPS flat rate shipping versus published United Parcel Service and FedEx retail rates.
Small flat rate boxes vs. ground shipping. In this first comparison, I looked at shipping rates for 1, 3, and 5-pound packages that fit in the 8 11/16 inch by 5 7/16 inch by 1 3/4 inch small flat rate box versus a similar-sized package shipped via UPS Ground or FedEx Home Delivery.
In the examples, the packages are all shipped from Caldwell, Idaho, ZIP code 83607. The destinations, representing several shipping zones, are New York, Chicago, Dallas, San Diego, and Las Vegas.
The UPS and FedEx rates are based on delivery to a residential address. The USPS rates are for the commercial base tier. The FedEx rates do not include dimensional weight.
Finally, it is worth mentioning that while it is not shown on this table, the USPS supplies flat rate boxes free of charge. I merchant would need to pay about $1 per order or more to purchase a shipping box for UPS or FedEx.
For small packages, USPS flat rate boxes are difficult to beat, especially when a business is shipping across several zones. In many cases, it was half the cost to ship via a USPS flat rate box. The potential savings held true whether one compares USPS flat rate boxes to UPS Ground or FedEx Home Delivery.
| 1 Lb. Small Box | Destination (ZIP code) | USPS Rate | USPS Days to Deliver | UPS Ground Rate | UPS Ground Days to Deliver |
|---|---|---|---|---|
| New York, NY (10007) | $7.05 | 2 to 3 Days | $11.04 | 5 Days |
| Chicago, IL (60602) | $7.05 | 2 to 3 Days | $11.01 | 4 Days |
| Dallas, TX (75201) | $7.05 | 2 to 3 Days | $10.96 | 3 Days |
| San Diego, CA (92111) | $7.05 | 2 to 3 Days | $10.72 | 2 Days |
| Las Vegas, NV (89101) | $7.05 | 2 to 3 Days | $10.42 | 2 Days |
| 3 Lbs. Small Box | Destination (ZIP code) | USPS Rate | USPS Days to Deliver | UPS Rate | UPS Days to Deliver |
|---|---|---|---|---|
| New York, NY (10007) | $7.05 | 2 to 3 Days | $16.01 | 5 Days |
| Chicago, IL (60602) | $7.05 | 2 to 3 Days | $13.49 | 4 Days |
| Dallas, TX (75201) | $7.05 | 2 to 3 Days | $12.40 | 3 Days |
| San Diego, CA (92111) | $7.05 | 2 to 3 Days | $11.75 | 2 Days |
| Las Vegas, NV (89101) | $7.05 | 2 to 3 Days | $11.14 | 2 Days |
| 5 Lbs. Small Box | Destination (ZIP code) | USPS Rate | USPS Days to Deliver | UPS Rate | UPS Days to Deliver |
|---|---|---|---|---|
| New York, NY (10007) | $7.05 | 2 to 3 Days | $18.27 | 5 Days |
| Chicago, IL (60602) | $7.05 | 2 to 3 Days | $16.66 | 4 Days |
| Dallas, TX (75201) | $7.05 | 2 to 3 Days | $15.07 | 3 Days |
| San Diego, CA (92111) | $7.05 | 2 to 3 Days | $13.75 | 2 Days |
| Las Vegas, NV (89101) | $7.05 | 2 to 3 Days | $11.66 | 2 Days |
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| 1 Lb. Small Box | Destination (ZIP code) | USPS Rate | USPS Days to Deliver | FedEx Rate | FedEx Days to Deliver |
|---|---|---|---|---|
| New York, NY (10007) | $7.05 | 2 to 3 Days | $10.48 | 5 Days |
| Chicago, IL (60602) | $7.05 | 2 to 3 Days | $10.45 | 4 Days |
| Dallas, TX (75201) | $7.05 | 2 to 3 Days | $10.41 | 3 Days |
| San Diego, CA (92111) | $7.05 | 2 to 3 Days | $10.18 | 2 Days |
| Las Vegas, NV (89101) | $7.05 | 2 to 3 Days | $9.89 | 2 Days |
| 3 Lbs. Small Box | Destination (ZIP code) | USPS Rate | USPS Days to Deliver | FedEx Rate | FedEx Days to Deliver |
|---|---|---|---|---|
| New York, NY (10007) | $7.05 | 2 to 3 Days | $15.20 | 5 Days |
| Chicago, IL (60602) | $7.05 | 2 to 3 Days | $12.81 | 4 Days |
| Dallas, TX (75201) | $7.05 | 2 to 3 Days | $11.78 | 3 Days |
| San Diego, CA (92111) | $7.05 | 2 to 3 Days | $11.16 | 2 Days |
| Las Vegas, NV (89101) | $7.05 | 2 to 3 Days | $10.58 | 2 Days |
| 5 Lbs. Small Box | Destination (ZIP code) | USPS Rate | USPS Days to Deliver | FedEx Rate | FedEx Days to Deliver |
|---|---|---|---|---|
| New York, NY (10007) | $7.05 | 2 to 3 Days | $17.35 | 5 Days |
| Chicago, IL (60602) | $7.05 | 2 to 3 Days | $15.82 | 4 Days |
| Dallas, TX (75201) | $7.05 | 2 to 3 Days | $14.31 | 3 Days |
| San Diego, CA (92111) | $7.05 | 2 to 3 Days | $13.06 | 2 Days |
| Las Vegas, NV (89101) | $7.05 | 2 to 3 Days | $11.07 | 2 Days |
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Large flat rate boxes vs. ground shipping. In this next set of price comparisons, I looked at shipping a 5, 10, and 15-pound package in a USPS large flat rate box versus shipping a similar package via UPS Ground or FedEx Home Delivery.
In these examples, there are many times when shipping a 5-pound box via UPS and FedEx Home was less expensive than the USPS, especially across a couple of zones. As the number of zones and the weight increases, however, USPS flat rate shipping becomes a very competitive option. At 15 pounds, an online shipper might save 50 percent.
I used the same ZIP codes as above, aimed at residential deliveries.
| 5 Lbs. Large Box | Destination (ZIP code) | USPS Rate | USPS Days to Deliver | UPS Ground Rate | UPS Ground Days to Deliver |
|---|---|---|---|---|
| New York, NY (10007) | $17.65 | 2 to 3 Days | $19.92 | 5 Days |
| Chicago, IL (60602) | $17.65 | 2 to 3 Days | $18.15 | 4 Days |
| Dallas, TX (75201) | $17.65 | 2 to 3 Days | $16.70 | 3 Days |
| San Diego, CA (92111) | $17.65 | 2 to 3 Days | $14.70 | 2 Days |
| Las Vegas, NV (89101) | $17.65 | 2 to 3 Days | $12.09 | 2 Days |
| 10 Lbs. Large Box | Destination (ZIP code) | USPS Rate | USPS Days to Deliver | UPS Ground Rate | UPS Ground Days to Deliver |
|---|---|---|---|---|
| New York, NY (10007) | $17.65 | 2 to 3 Days | $25.83 | 5 Days |
| Chicago, IL (60602) | $17.65 | 2 to 3 Days | $22.30 | 4 Days |
| Dallas, TX (75201) | $17.65 | 2 to 3 Days | $20.70 | 3 Days |
| San Diego, CA (92111) | $17.65 | 2 to 3 Days | $18.44 | 2 Days |
| Las Vegas, NV (89101) | $17.65 | 2 to 3 Days | $13.75 | 2 Days |
| 15 Lbs. Large Box | Destination (ZIP code) | USPS Rate | USPS Days to Deliver | UPS Ground Rate | UPS Ground Days to Deliver |
|---|---|---|---|---|
| New York, NY (10007) | $17.65 | 2 to 3 Days | $37.70 | 5 Days |
| Chicago, IL (60602) | $17.65 | 2 to 3 Days | $33.08 | 4 Days |
| Dallas, TX (75201) | $17.65 | 2 to 3 Days | $27.81 | 3 Days |
| San Diego, CA (92111) | $17.65 | 2 to 3 Days | $21.58 | 2 Days |
| Las Vegas, NV (89101) | $17.65 | 2 to 3 Days | $15.09 | 2 Days |
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| 5 Lbs. Large Box | Destination (ZIP code) | USPS Rate | USPS Days to Deliver | FedEx Rate | FedEx Days to Deliver |
|---|---|---|---|---|
| New York, NY (10007) | $17.65 | 2 to 3 Days | $17.35 | 5 Days |
| Chicago, IL (60602) | $17.65 | 2 to 3 Days | $15.82 | 4 Days |
| Dallas, TX (75201) | $17.65 | 2 to 3 Days | $14.31 | 3 Days |
| San Diego, CA (92111) | $17.65 | 2 to 3 Days | $13.06 | 2 Days |
| Las Vegas, NV (89101) | $17.65 | 2 to 3 Days | $11.07 | 2 Days |
| 10 Lbs. Large Box | Destination (ZIP code) | USPS Rate | USPS Days to Deliver | FedEx Rate | FedEx Days to Deliver |
|---|---|---|---|---|
| New York, NY (10007) | $17.65 | 2 to 3 Days | $24.53 | 5 Days |
| Chicago, IL (60602) | $17.65 | 2 to 3 Days | $21.18 | 4 Days |
| Dallas, TX (75201) | $17.65 | 2 to 3 Days | $19.66 | 3 Days |
| San Diego, CA (92111) | $17.65 | 2 to 3 Days | $17.51 | 2 Days |
| Las Vegas, NV (89101) | $17.65 | 2 to 3 Days | $13.06 | 2 Days |
| 15 Lbs. Large Box | Destination (ZIP code) | USPS Rate | USPS Days to Deliver | FedEx Rate | FedEx Days to Deliver |
|---|---|---|---|---|
| New York, NY (10007) | $17.65 | 2 to 3 Days | $35.83 | 5 Days |
| Chicago, IL (60602) | $17.65 | 2 to 3 Days | $31.42 | 4 Days |
| Dallas, TX (75201) | $17.65 | 2 to 3 Days | $26.41 | 3 Days |
| San Diego, CA (92111) | $17.65 | 2 to 3 Days | $20.50 | 2 Days |
| Las Vegas, NV (89101) | $17.65 | 2 to 3 Days | $14.33 | 2 Days |
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USPS flat rate vs. other flat rate shipping. Although the USPS is the first carrier to offer flat rate shipping, it is not the only option. For example, FedEx has its One Rate service.
The table below compares three popular box sizes for FedEx and the USPS. The FedEx One Rate is really three rates. There is a local rate, which is within 150 miles of the shipper’s location. There is a regional rate for shipments between 151 and 600 miles. And the national rate is for shipments traveling more than 600 miles.
| USPS Flat Rate Boxes | FedEx One Rate Boxes | Dimensions of Box | Rates (Local, Regional, National) | ||
|---|---|---|---|---|---|
| Small Box | 8 11/16″ x 5 7/16″ x 1 3/4″ | $7.05 | Small Box | 8 3/4″ x 2 5/8″ x 11 1/4″ | $8.65, $9.90, $10.95 |
| Medium Box | 11 1/4″ x 8 3/4″ x 6″ or 14″ x 12″ x 3 1/2″ | $12.85 | Medium Box | 8 3/4″ x 4 3/8″ x 11 1/4″ | $11.20, $13.50, $13.75 |
| Large Box | 12 1/4″ x 12 1/4″ x 6″ | $17.65 | Large Box | 8 3/4″ x 7 3/8″ x 11 1/4″ | $17.30, $18.80, $19.05 |
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Preserve Margins
In a competitive market where the trend is to offer free shipping to every customer regardless of order size, using USPS flat rate boxes can help merchants preserve margins. USPS flat rate boxes typically ship faster than ground shipping, potentially improving the shopper’s experience.