> ## Documentation Index
> Fetch the complete documentation index at: https://docs.shovels.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# State and Zip Code Validation in Address Searches

> Understand how the Shovels API handles state and zip code validation in address searches and what to expect with incorrect location parameters.

When using Shovels' API for address searches, it's important to understand how state and zip code parameters are processed.

## Key Behavior

**State and zip code parameters are not strictly validated** as part of geo\_id resolution.

If you provide an incorrect state or zip code when searching for addresses:

* You won't receive an explicit error message
* The API returns a 200 OK response with an empty result set (`null` items)

## Why This Happens

This behavior is by design to accommodate variations in how addresses might be recorded across different jurisdictions.

## Best Practices

For the most reliable results:

1. **Focus on the street address** - Street name, number, and city are most important
2. **Verify location data** - Double-check state and zip codes before querying
3. **Handle empty results** - If you consistently get empty results for addresses you expect to find, verify the state and zip information

<Info>
  Our system uses multiple address verification sources to ensure accuracy:

  * National Address Dataset from the US Census
  * Open Address dataset
  * Simple Maps
  * ESRI
</Info>

## Interpreting Empty Results

An empty result set can mean:

* The address exists but with different state/zip information
* The address doesn't have permits in our system
* There's a formatting mismatch in your query

## Troubleshooting

If you're getting unexpected empty results:

1. Try the query with just the street address and city
2. Verify the state abbreviation is correct (use 2-letter codes)
3. Check that the zip code matches the city
4. Search at a broader geography level first (city or zip) to confirm coverage

## Related Articles

* [Resolving addresses](/docs/knowledge-base/api/address-resolution/resolving-addresses)
* [Error handling](/docs/knowledge-base/api/errors/error-handling)