How Fast Is USPS Flat Rate Shipping? (+ Other FAQs)

USPS has a wide array of shipping services available to consumers to meet their shipping needs, and one of the most popular is Flat Rate shipping.

So, how fast is USPS Flat Rate shipping? Also, how does it work, and what does it cost? I’ve researched the matter in-depth, and here’s everything I discovered!

How Fast Is USPS Flat Rate Shipping?

USPS Flat Rate shipping is Priority Mail, which is delivered within one to three days. Flat Rate packages purchased under Priority Mail Express will deliver faster, within one to two days. Moreover, all Flat Rate pricing is determined by the dimensions of the box purchased and the delivery category.

Read on to learn more about USPS Flat Rate shipping and how to use it!

What Is USPS Flat Rate Shipping?

USPS Flat Rate shipping is a type of shipping service available under the Priority Mail or Priority Mail Express categories of USPS.

For example, USPS Flat Rate shipping allows customers to purchase a box at a flat rate and ship it regardless of the weight for one fixed price.

Flat Rate shipping prices can vary, of course, weight like a typical package would.

Typically, a flat rate box price only varies depending on where you’re shipping the package and which delivery category it falls under (Priority Mail or Priority Mail Express).

How Much Does USPS Flat Rate Shipping Cost?

The package’s weight, dimensions, and distance traveled determine most USPS shipping costs.

However, what makes USPS Flat Rate shipping different is that it only takes into account the distance and dimensions of the box, saving you money.

That said, USPS Flat Rate shipping boxes come in four sizes (with more sizes available for envelopes): small, medium one, medium two, and large.

Further, the small Flat Rate box is 8 5/8″ x 5 3/8″ x 1 5/8″ in size and is about $9, making it great for small electronics.

Then, the medium one Flat Rate box is 11″ x 8 1/2″ x 5 1/2″ in size and starts at $14.50, and is the perfect size for shoes and small board games.

Next, the medium two Flat Rate box is 14″ x 12″ x 3 1/2″ big and is side-loading rather than top-loading, which makes it perfect for awkwardly sized office supplies and costs the same as the medium one Flat Rate box.

Finally, the large Flat Rate box is, as expected, the largest of all of the Flat Rate boxes, coming in at 12″ x 12″ x 5 1/2″ in size.

Moreover, the large Flat Rate box starts at around $20 and is best for items such as laptops.

Is USPS Flat Rate Or Priority Mail Faster?

Is USPS Flat Rate Or Priority Mail Faster?

Priority Mail and Priority Mail Express are the fastest shipping services USPS offers.

With that, USPS Flat Rate shipping is a type of Priority Mail, so it’s just as fast as Priority Mail, which is the fastest you can get!

Additionally, Priority Mail Express usually delivers within one to two days, making it slightly faster than Priority Mail, which delivers in two to three days.

How Do You Use USPS Flat Rate Shipping?

To use USPS Flat Rate shipping for your package, you have a few options available to you.

For example, if you’d like to avoid making a trip to the post office, you can order your Flat Rate boxes online on this page of the USPS website.

Then, you can print off a shipping label from the USPS site or an online shipping service.

Next, affix the label to your Flat Rate box and drop it off at a collection box near you, which you can find here by using the drop-down menu to select “Collection Boxes.”

But, if you’d prefer to have your local postal worker help you out, just drop by your local post office and grab one of the Flat Rate boxes.

Then, you can either load your Flat Rate box there or drive home to package everything and go back to the post office and have the person behind the counter print out a label and ship it for you.

What Features Does USPS Flat Rate Shipping Include?

USPS Flat Rate shipping is a subcategory of USPS Priority Mail and USPS Priority Mail Express, meaning it provides all of the same features as either of those categories.

If you’re using a Flat Rate box under Priority Mail Express, you can expect to receive a tracking number for your package.

Additionally, you receive up to $100 of package insurance coverage built-in to the price of your box.

However, if you’re opting to use a Flat Rate box under Priority Mail, then you’ll have access to a tracking number, as well as up to $50 of package insurance coverage at no extra charge.

Also, if you’d like to opt-in for a signature upon delivery feature or additional insurance coverage for your package, you can obtain them at an additional charge.

Moreover, if you’d like to find more information on adding features to your Flat Rate package and what it costs, you can check out this page on the USPS website.

To learn more about USPS, you can also read our posts on USPS click-n-ship, what are USPS shipping zones, and if USPS shipping labels expire.

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Marques Thomas

Marques Thomas graduated with a MBA in 2011. Since then, Marques has worked in the retail and consumer service industry as a manager, advisor, and marketer. Marques is also the head writer and founder of

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