How To Read A Nixie Label

By Paul Johnson, President CMS – Complete Mailing Solutions

Nixie Labels- Mysterious Hieroglyphics or Useful Information?

In our series focusing on how to reduce returned mail, we thought it would be useful to unveil the mystery of how to read the yellow nixie label on returned mail pieces.

Nixie labels are chockful of information. Let’s start with getting acquainted with the USPS systems that generate these labels.

The Postal Service utilizes two systems for forwarding and redirecting mail. Each system will generate a Nixie label:Undelivered envelope with yellow sticker

  1. PARS=Postal Automated Redirection System
  2. CFS=Computerized Forwarding System
    • RFS=Remote Forwarding System (a subset of CFS)


The Postal Automated Redirection System (PARS) identifies and redirects forwardable, machinable letter mail during processing. It handles 2 categories of mail: Carrier Identified Forwards (CIF) and Return to Sender (RTS).
The Postal Service uses the Computerized Forwarding System (CFS) to handle mail that is non-machineable, including letters, flats and parcels. There are two categories that CFS handles: Forwards and Nixies (Return to Sender).
Very simply, these two systems sort and process the mail, which includes:

  • Identifying whether the letter, flat or parcel has a correct address and is mailable
  • If not, if there is a Change of Address (COA) on record and can be forwarded
  • Determining whether the mail piece is Undeliverable As Addressed (UAA)
  • If it is undeliverable, following directions given from the Ancillary Endorsements, i.e.:
    • Forward the mail piece and notifying the sender
    • Return the mail piece with new address information (via the Nixie label)
    • Destroy the mail piece
  • Complete processing and delivering the mail

The Nixie labels generated by these two systems provide valuable information to the sender regarding why the mail piece cannot be delivered. Some of the reasons mail is Undeliverable As Addressed (UAA) that are mentioned on the Nixie label include whether:

  • A new mailing address exists for the recipient (a Change of Address has been filed)
  • There is no forwarding address (often because the recipient did not fill out a Change Of Address (COA) with the Post Office
  • The Change of Address has expired (COA’s cover a one-year period)
  • There are errors in the address
    • Missing information
    • Incorrect information
  • The address does not exist (Address Unknown)
  • The location is vacant
  • A mail receptacle is not available

Additional details are listed on the label. The illustrations below identify the specific information that return labels contain for each of these two systems
(Click on each graphic for better visibility).

CFS RFS Nixie Label with arrows

Nixie labels are a valuable tool to keep your database up-to-date and ensure money is not spent on mail that will never reach the intended recipient. Ancillary Endorsements also play a helpful role. You can read more about Ancillary Endorsements in our earlier post: Ancillary endorsements – What are they? Why use them?
Contact us today for information on tools to reduce the number of Nixie labels you are receiving – 303-761-0681 or envelopes@cms-colorado.com

Ancillary Endorsements -What are they? Why Use them?

By Paul Johnson, President CMS – Complete Mailing Solutions

Ancillary Endorsements – Why do I care?

If you’re like most companies sending various communications to customers or prospects, you’re faced with an unfortunate fact – your mail doesn’t always reach it’s intended recipient without an ancillary endorsement. With over 11%* of the U.S. population moving each year, and 20% of new businesses failing in their first year+, keeping your mailing list up-to-date is an on-going challenge.
Given these stats, we have to ask: Why would you put anything in the mail if you weren’t 100% sure it would be delivered (especially invoices, statements, checks, etc.) or it would arrive with postage due? How would your Customers react?
We highly recommend you cleanse your database with CASS certified software annually, at a minimum. If for some reason that cannot happen, you’re next line of defense is to use Ancillary Service Endorsements on your envelopes.

What Are Ancillary Service Endorsements?

Ancillary Endorsements allow you to obtain an addressee’s new address (if a change-of-address has been filed with the USPS) or the reason why mail cannot be delivered. It tells the USPS how you want mail handled if there is a problem with the recipient and the address. For example whether you wish your mailpiece to be forwarded to the recipient’s new address, returned to you with updated address information, or destroyed. The endorsements include one keyword: “Electronic,” “Address,” “Return,” “Change,” or “Forwarding,” followed by “Service Requested.” Depending upon which endorsement you use, you’ll receive new address information, either on each mailpiece (via yellow “nixie” sticker) when it’s returned to you, or by a separate card if you want your mail piece forwarded.

Some of these services are free, others are not; for example, First-Class and Priority Mail do not incur fees for forwarding even without an endorsement (although you won’t know there’s a new address), whereas Marketing Mail and Package Services do incur fees for forwarding. The mailer is obligated to pay any applicable fees for forwarding, return and separate address notification charges. Check out the USPS Ancillary Service Endorsements Quick Service Guide for an overview of the specific endorsements available, actions and time limitations for each.

What Is That Yellow Sticker?

Ancillary Endorsements (e.g., Address Service Requested) alerts the Post Office what to do with your mail. The yellow “nixie” sticker on your mail piece alerts you of address changes and issues, such as:

  • The recipient is no longer at the address (unknown, moved, deceased). Notice may or may not have been given to the Post Office.
  • There is missing or incorrect address information (missing apartment or suite number, wrong city or ZIP code).
  • Mail was refused by the recipient
  • No postage was affixed

Why Use Ancillary Endorsements?

The use of Ancillary Endorsements initiates the flow of information from the Post Office, which will help you better manage your communications and avoid communicating with someone who is no longer there. Other benefits include:

  • Timely Information – you’ll receive updated information about the recipient, which will allow you to ensure future mailings are deliverable.
  • Improved Receivables – correct addresses ensure there is no delay in invoices or statements reaching recipients, which helps improve cash flow.
  • Lower Costs – having fresh address information ensures your mail gets to its recipient the first time, every time. No need to reprint and resend – a savings of $25 or more each mail piece! Surprised? See our earlier post on The Cost of Undeliverable Mail .
  • Clean Data – eliminates mailing to someone that may no longer be able to use your services because they have moved from your service area.

You’ll be able to better manage your database and mailings with the help of Ancillary Service Endorsements. 

Best Practices


We recommend the following:

  • CASS certify your data at least 1/x per year.
  • Print envelopes with endorsements. If your current envelope supplier doesn’t know about endorsements, call us about our envelope printing services and assistance with Endorsements.
  • Use your postage meter for Endorsements on the fly – call us to find out how.

Contact us today for information on other tools to keep your mailing lists up-to-date as well as help in determining the best Ancillary Service Endorsements for your mail – 303-761-0681 or envelopes@cms-colorado.com.

* U.S. Census Bureau, 2016 Current Population Survey Annual Social and Economic Supplement (CPS ASEC)
+ Bureau of Labor Statistics, Business Employment Dynamics, March 2016