What is a Carrier Route?

A postal carrier route is a group of mailing addresses that receive the same USPS code to ensure efficient mail and package delivery. For example, neighborhoods have the same carrier route. Carrier routes can include almost any type of dwelling or building, from offices to houses to condos to P.O. boxes. Every location that can receive mail is in a carrier route.

So a Carrier Route is Like a ZIP Code?

They’re similar in that they both help with mail delivery, but carrier routes are generally smaller than ZIP codes. There are roughly 600,000 carrier routes in the U.S. but only 40,000 ZIP codes, which means there’s an average of 15 carrier routes for every ZIP code. However, this isn’t true for all ZIP codes. Some ZIP codes have fewer or more carrier routes, ranging from just one carrier route per ZIP code to over 100 carrier routes.

What Does a Carrier Route Look Like?

A carrier route is composed of nine characters and includes both numbers and letters. The first five characters are digits that represent the ZIP code, the sixth character is a letter that defines the route type, and the last three characters are digits that represent the carrier route code.


51550 C 003
ZIP Code Route Type Carrier Route Code

Route Types

  • B = Post Office box (P.O. box)
  • C = City Delivery
  • C = City Delivery
  • H = Highway Contract
  • R = Rural Route

How Can I Use Carrier Route Data?

To access USPS carrier routes and see how they can help optimize your business’s mailing campaigns, simply sign up for an address verification service like CDYNE’s PAV API. Our API includes carrier route data as part of its postal address verification solution.

What Does Our PAV API Do?

Postal Address Verification (PAV) standardizes, corrects, and verifies addresses for deliverability before mail and packages are sent out. We help businesses ensure they have accurate, top-quality data and successful mailing campaigns.

Click the button below to read about our trusted three-step address verification process.

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Benefits of Using Carrier Routes

There are a variety of benefits when you utilize carrier routes in your mail marketing campaigns.

Increases ROI

Reduces Costs

Prevents Fraud

Saves Time

Fast Results

Quality Data


Great Coverage

When to Use Carrier Routes

Carrier routes are prime marketing tools for mailing campaigns. There are several different types of marketing that are most successful when paired with USPS carrier route data.

Marketing with Carrier Routes

Saturation Mailing

Saturation mailing is a type of targeted marketing campaign that sends mail to the majority of addresses in a carrier route. This type of marketing allows businesses to more easily focus on specific demographics or geographic areas.

Every Door Direct Mail

Every Door Direct Mail (EDDM) is a USPS mailing program that prioritizes simplicity. Businesses just choose a mail carrier route off the USPS website and their marketing materials will be delivered to all the addresses in the chosen carrier route.

Targeted Mailing Lists

Targeted mailing lists are even more specific than saturation mailing and allow businesses to segment their contacts based on a number of criteria. These criteria can include almost anything, from age to career to (you guessed it) carrier route.

The Perfect Fit for Your Company

You can use an address verification service like PAV to efficiently validate and send out all of the carrier route mailings listed below and more.

  • Product Catalogues
  • Industry Magazines
  • Free Trial Samples
  • Company Newsletters
  • Upcoming Event Flyers
  • Program Brochures
  • Appointment Reminders
  • Membership Renewal Forms
  • Event Registrations or RSVPs

Tools and Examples for Carrier Route Marketing

Imagine with us for a second. You’ve just opened an animal grooming business and want to get the word out to all of the local pet parents. There’s even a self-service bathing and blow-dry station for dogs, and every new customer who signs up for the loyalty program will get the first two baths free.

To let people know about your grand opening and loyalty offer, you decide to take advantage of mail marketing and send out a targeted mailing list. You know the local area is pretty pet-heavy but need more specific information.

What Next?

You know what a carrier route is, but what about how to effectively use it? There are two key tools to sending out successful campaigns.

Carrier Route Lookup

To see an official USPS carrier route map with boundaries, use a carrier route lookup tool and search a ZIP code. Deliverable addresses, the types of carrier routes, and more should be displayed.

Click here to try the USPS carrier route lookup.

Postal Address Verification

To make sure all of the addresses in your campaign are standardized and validated, use a postal address verification tool like PAV API. Maximize your ROI and stop worrying about undeliverable mail.

Click here to start your free PAV trial today.

How to Get Carrier Route Data for Your Business

To start incorporating carrier route data into your mailing campaigns, sign up for an address verification service like CDYNE’s PAV API. Our API returns carrier route data along with address standardization and validation information. Click here for a full list of all PAV return values.

PAV API and How it Works

PAV uses an efficient three-step process to ensure your mail and packages are deliverable. We standardize, correct, and validate bulk addresses in a fraction of a second.

Mailing Made Easy

1. Standardize

Standardization formats addresses to meet USPS standards.

2. Correct

Correction identifies and corrects wrong address information.

3. Validate

Validation uses the USPS databases to ensure address deliverability.

Carrier Route FAQs

A postal carrier route is a group of mailing addresses in the same geographic boundary that receive the same code to aid in efficient mail delivery.

Carrier routes are composed of nine characters. The first five are the ZIP code, the sixth is a letter representing the route type, and the last three are the carrier route code.

Carrier routes ensure efficient and correct mail delivery. They are just as important as the other elements in an address, such as the ZIP code and state.

Both the address and carrier route should be validated before sending mail out. CDYNE’s PAV API returns data on both to ensure successful delivery.

Emergency support is available. Please see our Contact page for more information.

Read our full list of general and technical FAQs.