USPS Regulations

Quick Guide: USPS Mail Class

How Mail Classes Differ

Your direct mail campaign can fall into one of several classes of mail used by the USPS, each with its own features and requirements. So which one should you use? Well, it mostly depends on the content of your mailing and its postage.

What follows is a quick breakdown of what each one is about – and how well it fits your goals.

Priority Mail

Need that special mail piece delivered fast? This is what to use for sending documents or merchandise weighing up to 70 pounds, and with a maximum size of 108″ in length and distance around thickest part combined. This service gets it there in about 2 days, whether it’s an envelope or a box. Unless specific Flat Rate packaging is used, pricing is determined by the number of “zones” it must travel from the mailing point to its destination.

Priority Mail Express

Need that special mail piece delivered really fast, like, tomorrow? This service, unlike Priority Mail, can guarantee next-day delivery. Besides the distance travelled, the weight of the mailer helps to set the postage price. Flat Rate packaging can make things cheaper, as can commercial rates, if certain requirements are met.

Media Mail

This is a relatively inexpensive option for mailing books, loose leaf binders, charts, and test materials. You can get a discount for presorting a campaign with a minimum of 300 pieces.

Library Mail

Academic institutions like museums, zoos, and yes, libraries, can mail books and other research material at special single piece and presort rates, based on weight.

Bound Printed Matter

If you’ve got something like a catalog that’s permanently bound with glue, staples, or stitching, you can use this class. Start with a permit imprint, and if you have 300 or more pieces, you can look at a variety of pricing options and discounts.


Lots of people still read magazines and newsletters! So long as your periodical meets specified restrictions, it can receive authorization from USPS for this special rate class. And mailers for nonprofits and classrooms get an additional price break.

Marketing Mail (the new “Standard Mail”)

This is for anything that’s not required to be mailed as First Class or Periodicals – such as flyers, circulars, or catalogs that are generally identical to each other and under 16 ounces each. It’s also known as “bulk” mail, so your quantities need to be 200 pieces or more, and delivery speed is slower than it is for First Class.

First Class Mail

These cards, letters, flats, and small parcels – which can’t weigh more than 13 ounces – are given priority over Marketing Mail, so the delivery time is pretty quick. And while anything mailable can be sent first class, certain types of pieces must use it, like bills, statements, personal correspondence, and handwritten material. Single-piece, commercial, and non-profit rates are available for presort and automation. Also – watch your sizes! Letter-sized pieces that are square or have some other non-machinable characteristic can’t be mailed at machinable rates.

At, we can help you create the right mailing campaign in the right class for your needs. And we have on-site USPS verification, so that your direct mail gets delivered on target and on time, saving you money!

Ideas to Use

  • Mail to the best-performing, top segment of your lists with Priority Mail and an irresistible offer. You’ll stand out and make the customer feel more special.
  • To ensure that your lists are up-to-date and won’t waste your money, First Class includes free forwarding and returns of mail that can’t be delivered to the original address; this costs extra for Marketing Mail.

USPS Postcard Rate

On January 21, 2018, the USPS postcard rate for a single postcard under First Class mail went up by one cent to 35 cents. But that’s for the single-piece rate, with a stamp. To mail at commercial rates, your campaign needs at least 500 pieces.

Let’s say that you have that amount and more. Depending on how your mail is printed and prepared, your bulk campaign can qualify for either machinable or automation rates.

Machinable means that you have an accurate address and have met the correct size and weight standards. The single presort price for a postcard is now 28 cents each.

Automation means that you’ve done some of the work for USPS by helping to process the mail with a delivery point or Intelligent Mail barcode. And you’ll have to meet certain design standards. Your postcard’s aspect ratio has to measure between 1.3 and 2.5; take the length of your postcard and divide it by the height to get that figure.

Here’s how you can save money.

USPS uses 3 levels of presort when pricing, 5-Digit, AADC, and Mixed AADC. With the 5-Digit tray preparation (mail with the same 5-digit zip code), the current per piece rate is 25.7 cents, a savings of up to 2 cents per postcard over the other 2 options.

Ideas to Use

  • As long as you meet thickness guidelines, use UV coating on the front side to make your postcard’s color images and graphics pop more.
  • On the address side, set up clear zones for the placement of postage indicia, IMb, and the address on the postcard. Consult the Domestic Mail Manual for more details.
  • If timing is not a big deal for your postcard campaign, you may want to use Marketing Mail instead of First Class. But remember: letters and postcards all mail at the same rates in that class. And you miss out on forwarding and return services that come with First Class.

Fortunately for everybody, USPS has several pre-processing address file tools to supplement commercial list hygiene solutions that are available.

For example, you can use Coding Accuracy Support System (CASS) certification to verify and standardize your addresses, and National Change of Address (NCOA) to catch any new movers. And bonus! They’ll also help you be eligible for automation discounts.

Know Your Formats

Mail has to comply with USPS regulations in order to get through its processing equipment. Normally, that isn’t a problem if you’re mailing standard envelope, postcard, and folded self-mailer formats.

But if you want to try a very different kind of mailpiece, talk to us or your printer first. They’ll know all about the right size, weight, postage, tabbing, and folding requirements to pass muster, or they’ll reach out to the USPS for an OK.