What is Address Validation?

Understanding Address Validation

Address validation provides the first line of defense against bad address data by catching obvious errors during data entry. When a user enters "123 Main" without a city or ZIP code, validation immediately identifies the missing components. If someone types "12345678" in a US ZIP code field, validation detects the invalid format. This real-time feedback prevents incomplete or obviously incorrect addresses from entering your database, improving data quality by 40-50% compared to unvalidated input.

The validation process applies rule-based checks without requiring external database lookups. For US addresses, validation checks that ZIP codes are 5 or 9 digits, state codes are valid two-letter abbreviations (CA, NY, TX, etc.), and all required components are present. For international addresses, validation ensures postal codes match country-specific formats - 6 digits for India, alphanumeric format for UK, and so on. Format validation can catch many errors instantly at minimal cost.

Modern address validation goes beyond simple presence checks to include consistency validation. A sophisticated validator might check that the city and state match the ZIP code range, flag suspicious patterns like all zeros or sequential numbers, detect common typos in city names, and verify that street numbers are reasonable (not negative or excessively large). These smart validations catch 60-70% of address errors without requiring postal database access.

The key distinction between validation and verification is the trade-off between speed/cost and accuracy. Validation happens instantly (5-20 milliseconds) with no per-request cost, making it ideal for real-time form checking. However, validation cannot confirm that "123 Main St, Springfield, IL 62701" is a real, deliverable address - it can only confirm it's properly formatted. Verification requires querying postal databases, takes longer (50-200ms), and typically has per-request pricing, but provides 95-99% deliverability confirmation.

For optimal results, many applications use both approaches in sequence: validation for instant user feedback during data entry, followed by verification for critical addresses before final submission. This combination provides the best user experience (immediate error detection) while ensuring deliverability (postal database confirmation). E-commerce platforms commonly validate addresses client-side in the browser, then verify server-side before processing orders, catching errors at both stages.

How Address Validation Works

Key Benefits of Address Validation

Common Use Cases

Address Validation vs Address Verification

How to Implement Address Validation with Sthan.io

Sthan.io provides both validation and verification. Use validation for quick format checks, verification for deliverability. Here's how:

POST https://api.sthan.io/v1/validate/address
Content-Type: application/json
Authorization: Bearer YOUR_API_KEY

{
  "street": "123 Main St",
  "city": "Austin",
  "state": "TX",
  "zipCode": "78701"
}

{
  "status": "valid",
  "checks": {
    "hasStreet": true,
    "hasCity": true,
    "hasState": true,
    "hasZipCode": true,
    "zipCodeFormat": "valid",
    "stateCodeValid": true
  },
  "warnings": [],
  "errors": [],
  "message": "Address format is valid"
}

Frequently Asked Questions

Related Terms