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

# IDV Errors & Edge Cases

> Common verification errors, failure modes, and how to handle edge cases.

## IDV Errors & Edge Cases

### Phone Verification Failures

| Error                                                    | Cause                                                             | Resolution                                                                                                                           |
| -------------------------------------------------------- | ----------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------ |
| `VERIFICATION_SESSION_EXPIRED` (19001)                   | Session not completed within the 10-minute window                 | Create a new verification session. Consider adding a timer or progress indicator to your UX.                                         |
| `VERIFICATION_SESSION_FAILED_INCORRECT_SMS_CODE` (19002) | User entered the wrong SMS code                                   | Create a new verification session. Confirm the user is entering the code from the most recent SMS.                                   |
| `VERIFICATION_SESSION_FAILED_SNA` (19003)                | User not on a mobile device, or on an unsupported carrier/network | Fall back to SMS verification. SNA access attempts are limited to 5 per session.                                                     |
| `ENTITY_PHONE_VERIFICATION_MAX_ATTEMPTS`                 | Too many verification attempts for this Entity's phone number     | The underlying SMS provider has rate-limited this phone number. Wait before retrying, and surface appropriate messaging to the user. |

### Identity Verification Failures

| Error                                                | Cause                                                                                           | Resolution                                                                                                                                                                               |
| ---------------------------------------------------- | ----------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `MISSING_IDENTITY_MATCH`                             | Method couldn't correlate the Entity's PII to a known identity — insufficient or incorrect PII  | [Update the Entity](/reference/entities/update-entity) with additional fields (DOB, SSN, address) and retry. See [Maximizing Success](/guides/identity-verification/maximizing-success). |
| `VERIFICATION_SESSION_FAILED_INVALID_ANSWER` (19004) | User answered one or more KBA questions incorrectly, or a question was missing from the request | Create a new verification session — a fresh set of questions will be generated. Confirm the user is answering carefully.                                                                 |
| `VERIFICATION_SESSION_EXPIRED` (19001)               | Session not completed within the 10-minute window                                               | Create a new verification session.                                                                                                                                                       |

### Request Errors

| Error                              | Cause                                                                                        | Resolution                                                                        |
| ---------------------------------- | -------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------- |
| `MISSING_PHONE_VERIFICATION`       | Attempted to create an identity verification session before phone verification was completed | Complete phone verification first, then create the identity verification session. |
| `EXISTING_VERIFIED_SESSION`        | The Entity has already completed verification for that type (phone or identity)              | No action needed — the Entity is already verified for that step.                  |
| `INVALID_ENTITY_TYPE`              | Attempted to create a verification session on a corporation Entity                           | Verification sessions are only available for Entities of type `individual`.       |
| `UNAUTHORIZED_VERIFICATION_METHOD` | The team is not authorized to use the requested verification method                          | Contact your Method CSM to enable the method (e.g., `byo_sms`, `byo_kyc`).        |

### Edge Cases

<Accordion title="User needs a different phone number mid-flow">
  An Entity's phone number cannot be changed once it has been set. If the user entered the wrong phone number, you'll need to create a new Entity with the correct phone number and start the verification process from the beginning.
</Accordion>

<Accordion title="Same phone number across multiple Entities">
  Multiple Entities can share the same phone number, but each Entity must complete its own verification independently.
</Accordion>

<Accordion title="Re-verification after Entity was previously verified">
  Attempting to create a verification session for an already-verified type will return `EXISTING_VERIFIED_SESSION`. Verification is persistent and does not need to be repeated.
</Accordion>

<Accordion title="Attempting verification on a disabled Entity">
  Verification sessions cannot be created for Entities that have been disabled. Ensure the Entity is in an active state before initiating verification.
</Accordion>

<Accordion title="Corporation Entity">
  Verification sessions are only available for individual Entities. Attempting to create a session on a corporation Entity will return `INVALID_ENTITY_TYPE`.
</Accordion>

### Error Code Reference

For the full list of error codes with response bodies, see the [Entity Verification Session Errors](/reference/errors/entity-verification-session-errors) reference.