What Is CASS Certification?

## CASS Overview

CASS — Coding Accuracy Support System — is a program run by the USPS that certifies address-matching software. Only CASS-certified software can generate the ZIP+4 codes and delivery point barcodes required for postal discounts.

## How Certification Works

| Step | Description |
|------|------------|
| Application | Vendor applies to USPS NCSC |
| Test data | USPS provides standardized test addresses |
| Processing | Vendor runs addresses through their software |
| Scoring | USPS evaluates match rates and accuracy |
| Certification | Valid for ~12 months (18-month cycle) |

The test dataset includes addresses with common problems: misspellings, missing apartments, old street names, and ambiguous city names.

## What CASS Software Does

When you run an address through CASS-certified software, it:

1. **Parses** the address into components (street, city, state, ZIP)
2. **Standardizes** abbreviations (St → Street, Apt → Apartment)
3. **Validates** against the USPS address database
4. **Corrects** minor errors (typos, wrong city names)
5. **Appends** ZIP+4, carrier route, and delivery point codes
6. **Flags** undeliverable addresses

## DPV: Delivery Point Validation

DPV is an add-on to CASS that confirms whether an address is an actual delivery point. CASS alone verifies the range (e.g., 100-200 Main St exists); DPV confirms the specific number (e.g., 153 Main St is deliverable).

## LACSLink and SuiteLink

Two additional CASS components:

- **LACSLink** — Converts rural route addresses to street-style addresses (e.g., RR 2 Box 100 → 123 Oak Lane)
- **SuiteLink** — Appends suite/unit numbers to business addresses

## Who Needs CASS?

Any organization that:

- Sends bulk mail and wants postal discounts
- Maintains a customer database and needs clean addresses
- Ships products and wants to reduce undeliverable packages
- Processes government forms requiring standardized addresses

Major CASS-certified vendors include Melissa, Smarty, AccuZIP, and BCC Software.