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USPS v3 Address Validation in 30 Seconds
·3 min read·By RevAddress·Quickstart
The USPS v3 REST API replaced the old Web Tools XML API in January 2026. Address validation is one call — no XML parsing, no USERID registration, no SOAP envelopes.
One curl command
Validate an address
curl "https://api.revaddress.com/api/address/validate?streetAddress=1600+Pennsylvania+Ave+NW&city=Washington&state=DC&ZIPCode=20500" \
-H "X-API-Key: rv_live_your_key_here"That returns a clean JSON response:
Response
{
"address": {
"streetAddress": "1600 PENNSYLVANIA AVE NW",
"city": "WASHINGTON",
"state": "DC",
"ZIPCode": "20500-0003"
},
"deliveryPoint": "00",
"carrierRoute": "C000",
"DPVConfirmation": "Y",
"vacant": "N"
}DPVConfirmation: "Y" means USPS confirmed this is a real, deliverable address. No guessing.
Python and Node.js
SDK examples
from usps_v3 import USPSClient
client = USPSClient(api_key="rv_live_your_key_here")
result = client.addresses.validate(
street_address="1600 Pennsylvania Ave NW",
city="Washington",
state="DC",
zip_code="20500",
)
print(result.address.street_address)
# 1600 PENNSYLVANIA AVE NWBoth SDKs are open source: Python (PyPI) · Node.js (npm)
What you get back
| Field | Meaning |
|---|---|
DPVConfirmation |
Y = deliverable, N = not deliverable, D = missing secondary (apt #) |
carrierRoute |
USPS carrier route code |
deliveryPoint |
2-digit delivery point for barcode generation |
vacant |
Y if USPS flagged as vacant |
Batch validation
Need to validate hundreds of addresses? Use the batch endpoint (Growth tier, up to 50 per call):
Batch request (up to 50 at once)
curl -X POST "https://api.revaddress.com/api/batch/validate" \
-H "X-API-Key: rv_live_your_key_here" \
-H "Content-Type: application/json" \
-d '{
"addresses": [
{"streetAddress": "1600 Pennsylvania Ave NW", "city": "Washington", "state": "DC"},
{"streetAddress": "350 Fifth Avenue", "city": "New York", "state": "NY", "ZIPCode": "10118"}
]
}'Next steps
- Batch validation tutorial — validate 50 addresses in one call
- Full API reference — request/response examples, live try-it, and admin diagnostics
- Interactive API docs — try requests live in the browser
- Rate limit guide — understand the 60/hr USPS cap and how we handle it
- Migration guide — converting from Web Tools XML
- Get your API key — free to start, no credit card required
Keep the free proof wedge first
USPS v3 developer toolkit. Free tier for validation and rates. Flat monthly pricing.
Validation, ZIP+4, and rates are the free proof path. Labels, tracking, BYOK, and pickup stay protected until the workflow and proof gates are actually ready.