Address Standardization for Direct Mail Marketing

Direct mail campaigns are billed per piece sent. Every undeliverable piece caused by a bad address is pure wasted spend.

The problem

Mailing lists are assembled from many sources — CRM exports, purchased lists, web forms — each with its own formatting quirks. Sent as-is, inconsistent formatting increases the undeliverable rate and can trigger postal-service bulk-mail formatting penalties.

How address standardisation helps

Standardising every record in the list into canonical components and fully expanded strings (expansions) standardizes the mailing list before it goes to print. The expansions array standardizes street types and PO Box designations, making it straightforward to deduplicate recipients and eliminate undeliverable postage waste.

Example

POST /v1/address/normalize

curl -X POST "https://api.goodvat.com/v1/address/normalize" \
  -H "Authorization: Bearer $GOODVAT_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "query": "PO Box 4501, Portland OR 97208" }'

200 OK

{
  "poBox": "po box 4501",
  "postcode": "97208",
  "city": "portland",
  "state": "or",
  "country": "USA",
  "expansions": [
    "po box 4501 portland or 97208 usa",
    "po box 4501 portland oregon 97208 usa"
  ]
}

Key response fields

Field	Why it matters here
expansions	Standardized canonical strings used to deduplicate mailing lists across diverse input files.
poBox	Correctly separated from street-address fields — mixing the two is a primary cause of misdelivery.
postcode	Drives postal sortation and bulk-mail discount qualification.
city / state	Required for standard mailing-address postal compliance.