Returned Mail: Why It Happens, Ways to Prevent It

At A Glance

The United States Postal Service (USPS) and Canada Post may also dispose of packages that they are unable to deliver, resulting in more substantial financial losses and waste — not to mention, the potential for unhappy customers.

Many of these delivery failures are preventable. Address verification services are available to validate the accuracy of a recipient’s location, before a mistake happens.

Keep reading to learn how to reduce failed deliveries, which have the potential to create obstacles for your business, waste already-strapped resources, and cause frustration for your customers.

Returned Mail Overview

Background: USPS and Canada Post

Across North America, the USPS and Canada Post are some of the most elaborate and well-planned mail delivery systems in the world.

The USPS has an annual operating revenue of more than $71B and delivers 48 percent of the world’s mail. It is self-funded through revenues from stamps and other service fees rather than tax dollars. 

The backbone of the USPS is its integrated supply chain, which partners with private companies to deliver mail to 160M+ delivery addresses, which includes 46M rural addresses. 

In Canada, the postal service is an independent corporation, similar to the United States and generated around $8.9B CAD in 2019. Canada Post was originally a part of the government until the 1960s and became privatized in 1981.  

Similar to USPS, Canada Post is able to deliver mail to every one of Canada’s 16.M+ addresses. Canada Post is the only carrier in the country that is able to meet that level of scale with 21 mail processing plants, 477 delivery depots, and 13,000 corporate vehicles.

Both USPS and Canada Post rely on well-defined addressing systems to ensure that mail reaches its correct destination across this supply chain network.

Postal Code Lookup

Why It Happens

Here are the most common reasons, according to both carriers, for why mail doesn’t reach its intended recipient:


Canada Post

  • No postage
  • Incomplete, illegible, or incorrect address
  • The addressee isn’t at the address
  • The addressee refuses the mail at the time of delivery
  • The minimum criteria for mailability isn’t met
  • The address doesn’t exist
  • The address is incorrect
  • The addressee has moved without providing a forwarding address
  • The addressee refuses the item
  • The item contains insufficient postage


The USPS explains that mail may be undelivered due to changes happening with addresses behind the scenes. These situations include:

  • Renumbering of houses
  • Renaming of streets
  • Conversion from rural to urban addresses
  • Realignment of highway routes
  • Consolidation of routes
  • Consolidation of post offices
  • Changes in delivery districts

Last mile delivery, the final stretch from a delivery hub to a destination, can sometimes represent 25% of shipping costs due to the complexity of delivering packages to some locations. Most delivery problems happen within the last mile.

According to research from Loqate, 80% of failed retail deliveries are due to errors made by shoppers. This is due to the fact that they enter incorrect address data in the checkout – perhaps because they are in a hurry, not concentrating properly or just making a simple typo.

Address Validation As A Solution

Address validation, also known as address verification, is a technique for cross-referencing postal information with an official dataset in order to check the accuracy of information before you send mail or packages.

For instance, an eCommerce company may use an address verification API (application programming interface) to auto-complete address form fields, so customers can check out faster. An insurance company may use an address verification API to research policy quotes for a specific geographic area. An address verification API will also ensure that information that a customer inputs is accurate, to avoid returned mail.

There are a number of address verification services and API solutions available to meet different business requirements and needs. Here are some criteria to consider when selecting address verification technology for your business:

  • Frequency of data updates
  • Processes for safeguarding company data
  • Uptime standards
  • Ability to address typos
  • Data sources and their integrity
  • Integration and deployment time
  • Back-end address verification services to cleanse, parse, and standardize data in integrated software
  • Global data coverage
  • Additional services
  • Additional datasets
  • Customer support options
  • Integrations with multiple postal carriers
  • Third-party application development
  • Correcting customer-generated errors
  • Building a rich database
  • Maintaining CRM hygiene

Successful address verification strategies support higher level business goals such as error reduction, database enrichment, and delivery speed. With fewer delivery failures, businesses can run at maximum efficiency.

Loqate have put together a whitepaper which investigated the far-reaching impacts of failed deliveries for retailers and consumers. Download your copy of our Fixing Failing Deliveries whitepaper here.

Loqate helps businesses around the world verify customer addresses by combining our global datasets with best in class technology. Our easy to integrate API helps our customers verify customer data at the point of capture. Find out more about how Loqate address verification solutions can help your business.