> ## Documentation Index
> Fetch the complete documentation index at: https://nayax-44d6e37b-docs-marshall-faq-redistribution.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Error Codes

This page provides a reference of error codes. All errors share the same response structure and are returned in the `errorCode` and `errorMessage` fields.

### Protocol Errors

| Code     | Meaning                                 |
| :------- | :-------------------------------------- |
| **1001** | Invalid JSON                            |
| **1002** | Unknown command                         |
| **1003** | Required parameter missing              |
| **1004** | Parameter invalid value                 |
| **1005** | Invalid `displayInput` prompt signature |

### Payment Errors

| Code     | Meaning                 |
| :------- | :---------------------- |
| **2001** | Try another card        |
| **2002** | Use magnetic reader     |
| **2003** | Please check your phone |
| **2004** | Use contact reader      |
| **2005** | Card blocked            |
| **2006** | Present one card only   |
| **2007** | Transaction canceled    |
| **2008** | General payment error   |
| **2009** | Remove card             |
| **2010** | Remove card beep        |
| **2011** | Card removed            |
| **2012** | Use smart card reader   |

### General Errors

| Code     | Meaning            |
| :------- | :----------------- |
| **3001** | FuelApp error      |
| **3002** | VPOS service error |

### Error Handling Best Practices

To ensure a high-quality integration, follow these guidelines:

* **Logging**: Always log both the `errorCode` and the descriptive `errorMessage` to facilitate debugging.
* **Retries**: Implement client-side retry logic if the terminal does not respond within the expected window.
* **Safety**: Never automatically retry a declined transaction without a direct user action.
* **Typical Timeouts**: Use the following time windows for client-side monitoring:
  * **Card Detection:** 30–60 seconds.
  * **User Input:** 60–120 seconds.
  * **Authorization:** 10–30 seconds.

<Note>
  **User Feedback**
  Always provide clear visual feedback on the POS screen during wait times or when an error occurs to keep the customer informed.
</Note>