The most common type of bulk mail is called "Standard Class". Most advertising mail, newsletters, etc. are sent using Standard Class. Standard Class bulk mail has one level of discount postage rates for commercial mailers, and substantially greater discounts for approved nonprofit organizations.

Postage Saver Low-Cost Software for Postal Bulk Mail Unfortunately, there is no single postage rate that applies to all commercial or nonprofit Standard Class bulk mail. In fact, in any Standard Class bulk mailing, there's a pretty good chance that you'll pay several different postage rates on different pieces, depending on where the pieces are going.

Rates depend on the size category and weight of the pieces being mailed, along with where the pieces are going and what type of postal facility they are mailed from (and more....) You can use our Standard Class bulk mail rate calculator (below on this page) to see the relevant rates for the specific type of piece you are mailing.

This page is about Standard Class postcard, letter and flat sized mailings. For information about Standard Class parcels, please see our parcels help page.

What are the postage rates for Standard Class Bulk Mail?



Make sure you know whether your mail piece is a letter, a flat, or a parcel. That is determined by the size of the piece, not by what it contains.

For example, a 9 x 12 envelope containing a letter is considered a "flat" because of its size, while a 5 x 8 card is considered a "letter", even though most of us would call it a postcard.

Unlike First Class, Standard Class does NOT have a special, lower rate for 4 x 6 postcards. There is no difference in postage between a card and an envelope, as long as they are the same size.

For full information on the categories, see Letters vs. Flats.


The postage price for Standard Class bulk mail depends on the size and weight of the mail piece, and on how many pieces you have going to a particular zip code or area.

Also, Standard Class offers "entry discounts" for sending your mailing from a major sorting center. So, for a Standard Class mailing, there's a pretty good chance that you'll pay several different postage rates on different pieces in the same mailing, depending on where the pieces are going.

Nonprofits get additional discounts off of the commercial Standard Class rates.

You can use our Standard Class bulk mail postage price calculator to find the rates available for your mailing.

Standard Class Bulk Mail Postage Price Calculator


Make the following selections to find the postage prices for your Standard Class mailing:

Mailer is: commercial nonprofit
(Note that political candidate mailings are considered commercial.)

Select Mail Size:
letter - up to 6⅛" x 11½" x ¼"
flat - up to 12" x 15" x ¾"
Larger? Please see our parcels help page.
(There is no separate postcard rate for Standard Class. Cards are priced as either letters or flats depending on their size.)

Weight in ounces (must be less than 16):

For letters, does something (like an unusual shape) make this mailing
"nonmachinable"?  yes  no  See here for explanation.

Your 5-digit zip code:


The rate chart may use the terms "FSS", "ADC" and "AADC". Here's what they mean:
  • An FSS facility is a USPS sorting facility that has new high-speed flats sorting equipment. These are currently only in limited areas, but more are being added. If you are lucky enough to have mail going to zip codes served by an FSS, you get an extra postage discount.
  • ADCs and AADCs are Area Distribution Centers, mail sorting hubs that typically serve a large part of one or more states.
If you already have the list you want to mail to, we recommend you download a free demo copy of our Postage Saver bulk mail software, and run your list through it. It will figure out the exact postage you'd pay for mailing that specific list, and let you try various options.

There are additional discounts for mail sent to every address in an area, and for mail sent from USPS National Distribution Centers and Auxiliary Service Centers. Please contact us for more information if these situations apply to your mailing.

How many pieces do I need for Standard Class bulk mail?

To get Standard Class bulk mail pricing, you need to send at least 200 pieces or 50 pounds of mail at one time (whichever is less). You don't need to send a certain number of pieces to any particular zip code or part of the country, etc., as long as all of your mail is going to addresses within the United States (which can include military addresses, Puerto Rico and U.S. possessions). There are also no monthly or yearly quantity requirements.

What are the size and weight limits for Standard Class Bulk Mail?

The weight limit for Standard Class bulk mail depends on the size of the mail piece.
  • Standard Class letter-size mail may not weigh more than 3.5 ounces if it is barcoded, or must weigh less than 16 ounces if it is not barcoded.

  • Standard Class flat-size mail must weigh less than 16 ounces.
The longer side of each piece must be no more than 15 inches long. The shorter side must be no more than 12 inches long. The piece can be no more than 3/4" thick.

Pieces that are larger, or that aren't flexible enough to go through postal sorting equipment, may be able to be sent using Standard Class parcel service, or Parcel Select Lightweight service, which are very economical services for parcels under one pound. See our help page on saving money on bulk parcels.

Can I personalize Standard Class bulk mail?

In each mailing, your pieces must be essentially identical. However, you can include some personalized information on each piece, if it's directly related to the purpose of the mail. (Careful, the rules can be tricky. See our help page on the do's and don'ts of personalizing bulk mail.)

That means you may send form letters on which you personalize the name and address. And, if you follow the rules carefully, you can include some other personalized information, like the amount of a recent donation.

But, you can't scribble notes to your friends on various pieces. And you generally can't send invoices, statements, checks, or other similar mail using Standard Class.

(If you send mail like invoices, statements, or similar mail that is not eligible for Standard Class rates, and you send at least 500 pieces at one time, you can still get a small postage discount by using presorted First Class Mail.)

How do I pay the postage for Standard Class bulk mail?


Bulk Mail Indicia
if you buy a permit imprint authorization, you can print an "indicia" box like this on your mail instead of putting a stamp on each piece. That saves a lot of work! For details on what goes in the box, click here.
The most common way to pay your postage is to maintain an account at the post office. You just print a "postage paid" box, called an "indicia", on your mail pieces, instead of using stamps or a postage meter. Then, each time you bring in a mailing, USPS will verify your postage calculations and then make sure you have enough in your account to pay for your mailing.

To use an indicia on your mail, you must buy a "permit imprint authorization", which you can do when you apply for your mailing permit. There is a $215 one-time charge for the authorization.

Since the indicia is not really actual postage, you can design it as part of the printing on your mail piece, just like your return address. You don't need any special software to print an indicia.

Some mailers believe it is worth the effort to use stamps or a meter on their presorted mail, instead of an indicia, so it doesn't look like bulk mail. The choice is up to you.

How do I get started with Standard Class?

To learn how to get started and to prepare your first mailing with Standard Class bulk mail, see our Getting Started with Postal Bulk Mail page.