Coding Accuracy Support System (CASS)

Important Notice

Migration from CASS to our new improved CASS2 Product Feature must be completed by the end of July 2023

Please contact your customer success manager or account manager if you have any questions


The CASS™ certification process is designed in cooperation with the mailing industry to improve the accuracy of postal codes, i.e., Five-Digit ZIP Code®, ZIP + 4®, delivery point (DPCs), and carrier route codes that appear on mailpieces.

 Additional information on CASS can be found on the USPS site here.

 Platform Availability

 CASS is currently available for the following platforms:  

  • Windows 32
  • Windows 64
  • Linux 32
  • Linux 64 

Release Information

CASS library typically follows a 2-year cycle and it expires at the end of each cycle (July 31st every odd year). Data files used by CASS also expire at the end of the third month of release. For example, CASS data released in February expires at the end of Apr. You will see this represented in Loqate with an expiration date of May 1st (i.e. good until the end of April). This was a USPS driven change in October of 2022. (reference:

Please be aware that the CASS dataset expiration dates are set by the postal authority. Please ensure that you have the latest library and data installed to avoid loss of service through these products.

 CASS  & CASS2 are updated on a monthly basis and made available on the 15th of each month. Please check the latest release notes for expiration information. 

CASS Installation

For Windows installations, please ensure Loqate is installed outside of Program Files. Even if you enable read/write permissions while inside Program Files, there may still be permissions issues.

To check if CASS is installed run the following code from the command line:

lqtBatch.exe –d <data directory> (Windows)

./lqtBatch –d <data directory> (Linux)

If CASS is active, your console will display the following (you may need to search for “CASS” if the console output is very long): 

CASS API Status : Active

CASS Data Status : Active

CASS connection status : Success

DataBase Date : [YYYYMMDD]

DataBase z4Version : [0.00.00.N]

Name : CASSInfo

Number of days until API expires : [000]

Open lqtDemo.exe (Windows only), click on the tab labelled “GKR”, click “Browse” and select your Loqate Data folder. When the file drop-down has populated, scroll through the list and select “CASSInfo”. The expiry date will be on the output.


Updating CASS

To update CASS, run Install Manager following the instructions on the support site listed here.

On the data pack selection screen below, you will need to select both the library and USA Verify Dataset CASS. Please select the corresponding library for the platform you’re using.

CASS Library (Windows 32, Windows 64) or (Linux 32, Linux 64)
USA Verify Dataset CASS

Input Requirements

Loqate follows the same input format as USPS. Since it is a certified product, CASS process requires the below input format:  

  • Address1 (may contain Premise, Subbuilding, Thoroughfare)
  • Address2 (optional input field: Apt/Suite/Others)
  • Locality (may contain Locality only or Locality, AdministrativeArea, and PostalCode combined)
  • AdministrativeArea (if it is not in Locality field)
  • PostalCode (if it is not in Locality field)
  • DependentLocality (optional. urbanization for Puerto Rico addresses)
  • Organization (optional)

Stop Processing Event

CASS tool will stop processing when it detects false positive events. This is a security measure embedded in CASS tool. This security measure is designed to prevent the artificial creation of an address list by detecting when a submitted address appears to have been constructed artificially and not obtained legitimately.

When such event happens, please get ProcessResult’s status and error message and contact Loqate with this information.

PS Form 3553 Generation

To request the PS Form 3553 report file, add the following parameter to the batch command script.
-r PS3553

End users (mailers) will send PS Form 3553 to USPS along with the mailing list to receive a discount. The batch process will create a file named “PS3553_report.txt”.

Under section A1 on the PS3553 form, the Certified Company Name should be entered as LOQATE, and the CASS Certified Software Name & Version should be LOQATE ENGINE [version number] (e.g. 20.15.00.N).

To see a sample of the PS Form 3553, please click here.

Output Component Field

The following page outlines information regarding the CASS Fields:


Below is a list of available parameters: 

Parameter Description Example from Sample Script
-d The -d parameter is used to specify the location of the Loqate Global Knowledge Repository. The default value is “data/”, that is the ‘data’ subdirectory. -d data/
-p invokes the process -p cass
-i The -i parameter is used to specify the input UTF-8 text filename containing the data to be processed. Note: if the sample file isn’t in you Loqate API directory, you will need to specify the full path of the location -i sample.txt
-o The -o parameter is used to specify the output UTF-8 text filename to contain the processed data. Note: if a path isn’t specified, it will be printed in your current Loqate API folder. -o casstesting.txt
-oh The -oh parameter is used to specify that a header line should be output to the output file.
-of The -of parameter is used to specify the output file format using the same syntax as the -if parameter. A list of the default values can be found on the support site here. Important Note**: You will need to use this option to output the CASS fields.

Sample Script

Below is a sample script of how to run CASS: 

./lqtBatch.exe -d data/ -p cass -i sample.txt -o casstesting.txt -oh -of “AutoZoneIndicator|CarrierRoute|CMRAIndicator|










Troubleshooting Tips

  • Error message: “cass module could not be found”
    Step 1: check to ensure you have the library installed.
    Note: you don’t need to re-install. However, an easy way to check is to run Install Manager, if both the library and CASS datasets are not listed then you have it installed. If they are listed, then you will need to rerun Install Manager to install the missing components.Step 2:  Once you confirmed you have the required components; ensure you are in the correct installation directory of Loqate
  • Error message: CASS has expired – If you do not update your data, CASS will stop working and you will receive error message: “CASS has expired”
    Resolution: update CASS data using Install Manager. Please follow the section in this document titled: “How to update data pack”
  • Error message: Datapack installation was partial – this means that your datapack installation was interrupted. Usually due to internet connection issue or pause and restarting can cause issues as well.
    Resolution: Rerun Install Manager and select the packs that did not get updated. If you do not see the datapack available in the list, then that means you’ve already downloaded the datapack.
  • Error message: Disk space: Please ensure you have enough disk space to download, otherwise you will receive a size read error message.
    Resolution: If you are out of diskspace, please clear space and rerun install manager.