> ## Documentation Index > Fetch the complete documentation index at: https://docs.prelude.so/llms.txt > Use this file to discover all available pages before exploring further. # Troubleshooting errors (V1 API) > This page presents how to handle errors with our Legacy API, V1. The V1 API is **deprecated**. Starting November 1st 2025, no support will be provided for the V1 API and it will be **removed by April 2026**. No new features nor functionality will be added to the V1 API. Please use the [V2 Verify API](/verify/v2/documentation/introduction) instead. For more information refer to the [V2 Migration Guide](/verify/v2/documentation/v2-migration-guide). Prelude uses conventional HTTP [statuses](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status) to indicate the success or failure of a request: * Codes in the `2xx` range indicate success. * Codes in the `4xx` range indicate an error that failed given the information provided (e.g. required parameter was omitted or an authentication failed). * Codes in the `5xx` range indicate an error with Prelude's servers (these are rare). *** ## Codes Below is a list of possible error codes, along with additional information about how to resolve them. | Code | Description | | -------------------------- | ----------------------------------------------------------------------------------------------------------- | | `account_invalid` | The provided customer UUID is invalid. | | `bad_request` | The request was malformed. | | `blocked_number` | The phone number is in the blocklist. | | `internal_server_error` | An internal server error occurred. | | `invalid_app_version` | The provided application version is invalid. | | `invalid_auth_uuid` | The provided authentication UUID is invalid. | | `invalid_device_id` | The provided device ID is invalid. | | `invalid_device_model` | The provided device model is invalid. | | `invalid_line` | Prelude does not support this type of phone number. | | `invalid_os_version` | The provided OS version is invalid. | | `invalid_phone_number` | This is not a valid E.164 number. | | `invalid_sender_id` | The provided Sender ID is invalid. | | `invalid_template_id` | The provided template ID is invalid. | | `negative_balance` | You have a negative balance. | | `no_associated_auth_found` | The associated authentication was not found. | | `suspended_account` | Your account has been suspended. | | `unauthorized_sender_id` | The provided sender ID is not authorized to send messages. | | `unsupported_region` | Prelude does not support this region yet. | | `spending_limit_exceeded` | The spending limit for a time period has been exceeded. You can set the spending limits from the Dashboard. | | `impossible_code` | The provided code is impossible. | ***