> For the complete documentation index, see [llms.txt](https://docs.idlayr.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.idlayr.com/products/number-verification/discovery/error-codes.md).

# Error codes

{% hint style="info" %}
**Device API** · NV 1.0 · Early Access
{% endhint %}

Errors specific to Discovery. Two classes:

* **HTTP-response errors** — returned synchronously on API calls. RFC 7807 body with an `error_code`.
* **Terminal-state error codes** — carried in the DiscoveryCheck resource body when `status` is `ERROR` or `EXPIRED`.

This page lists only Discovery-specific codes. For the canonical, cross-product error catalogue with full semantics — see the [API Reference](https://docs.idlayr.com/api-reference). For client-side errors raised by the SDK before any HTTP request reaches IDlayr, see [SDK errors](/get-started/sdks/errors.md).

## HTTP-response errors

<table data-header-hidden="false" data-header-sticky><thead><tr><th width="96.265625">HTTP</th><th width="192.81640625">Error code</th><th>When</th></tr></thead><tbody><tr><td>400</td><td><code>invalid_request</code></td><td>Malformed request body</td></tr><tr><td>400</td><td>🆕 <code>invalid_ip</code></td><td>The IP address provided is missing or malformed.</td></tr><tr><td>400</td><td><code>bad_request</code></td><td>Malform request body</td></tr><tr><td>401</td><td><code>unauthorized</code></td><td>Your authentication token is missing, invalid, expired, or couldn't be verified. Get a new token and retry.</td></tr><tr><td>403</td><td><code>invalid_scope</code></td><td>Your credentials are valid but don't have permission for this endpoint or project. Request the correct scope for your token.</td></tr><tr><td>404</td><td><code>check_not_found</code></td><td>We couldn't find a check with this ID — it may be incorrect, expired, or already removed.</td></tr><tr><td>429</td><td><code>too_many_requests</code></td><td>Project rate limit exceeded</td></tr></tbody></table>

## Terminal-state error codes

Returned on the Discovery resource when `status` is `ERROR` or `EXPIRED`. The `error_code` field carries one of:

#### `status: ERROR` <a href="#status-error" id="status-error"></a>

<table><thead><tr><th width="212.97265625">Error Code</th><th width="88.29296875">HTTP</th><th>Explanation</th></tr></thead><tbody><tr><td>🆕 <code>invalid_ip</code></td><td>400</td><td>The IP address provided is missing or malformed.</td></tr><tr><td><code>not_mobile_ip</code></td><td>412</td><td>This request isn't coming from a mobile data connection, which this check requires.</td></tr><tr><td><code>mno_not_supported</code></td><td>422</td><td>We don't currently support this mobile operator.</td></tr><tr><td>🆕 <code>mno_not_enabled</code></td><td>422</td><td>This mobile operator isn't yet enabled for your project. Check your Approved Networks page, or request approval.</td></tr><tr><td>🆕 <code>service_unavailable</code></td><td>503</td><td>We're having a temporary issue on our side.</td></tr><tr><td><code>mno_server_error</code></td><td>200 (Error field)</td><td>The mobile operator's system returned an unexpected error.</td></tr><tr><td><code>mno_timeout</code></td><td>504</td><td>The request to the mobile operator's system timed out.</td></tr><tr><td><code>mno_response_error</code></td><td>200 (Error field)</td><td>The mobile operator's system sent back a response we couldn't understand.</td></tr><tr><td><code>mno_user_not_found</code></td><td>200 (Error field)</td><td>This phone number isn't recognized by the mobile operator for this check.</td></tr><tr><td>🆕 <code>mvno_not_supported</code></td><td>200 (Error field)</td><td>This phone number is from Mobile Virtual Network Operator that is not supported.</td></tr><tr><td><code>mno_no_data_available</code></td><td>200 (Error field)</td><td>The mobile operator isn't able to share the information needed for this check.</td></tr><tr><td><code>ip_mismatch</code></td><td>200 (Error field)</td><td>Your network connection changed partway through verification. Restart the check on a stable connection.</td></tr><tr><td><code>internal_error</code></td><td>500</td><td>Something went wrong on our end. Retry, and contact support if it persists.</td></tr></tbody></table>

#### `status: EXPIRED` <a href="#status-expired" id="status-expired"></a>

<table data-header-hidden="false" data-header-sticky><thead><tr><th width="252.8671875">Error code</th><th width="113.7578125">HTTP</th><th>Meaning</th></tr></thead><tbody><tr><td><code>redirect_not_performed</code></td><td>200 (status field)</td><td>The verification redirect was never executed by the device before the check expired</td></tr><tr><td><code>incomplete_redirect</code></td><td>200 (status field)</td><td>The verification redirect started but did not complete before the check expired</td></tr></tbody></table>

## Client-side SDK errors

If the SDK can't initiate the request, it returns a client-side error before any HTTP request reaches IDlayr. Same set as Secure SNA — see [SDK errors](/get-started/sdks/errors.md) for the cross-platform catalogue.


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