> ## 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.

# Understanding Permit Unique Identifiers

> Learn the difference between Shovels' unique permit ID and the jurisdiction-assigned permit number, and why using the correct identifier matters.

Each permit in Shovels has a unique identifier that distinguishes it from all other permits in our database.

## Shovels ID vs Permit Number

| Field          | Description                  | Uniqueness                           |
| -------------- | ---------------------------- | ------------------------------------ |
| **ID**         | Generated by Shovels         | Globally unique across all permits   |
| **permit\_no** | Assigned by the jurisdiction | Only unique within that jurisdiction |

## Why This Matters

Different jurisdictions may coincidentally assign the same `permit_no` to different permits. For example:

* Los Angeles might issue permit #12345
* San Francisco might also issue permit #12345

These are completely different permits, but they share the same permit number.

<Warning>
  Always use the Shovels `ID` field to organize data by unique permit identifiers, not `permit_no`.
</Warning>

## Using Shovels IDs

The Shovels ID:

* Remains persistent throughout the permit lifecycle
* Never duplicates across jurisdictions
* Enables reliable data joins and tracking
* Stays consistent across data refreshes

## Related Articles

* [Permit tracking](/docs/knowledge-base/data/permits/permit-tracking)
* [Data Dictionary](https://www.shovels.ai/data-dictionary)