# Tax Code Validation

> Check the formal validity and structure of an Italian tax code (Codice Fiscale) and get a quality flag and code that describe the result.

## Endpoint

`POST https://{host}:{port}/Egon/api/norm`

Replace `{host}` and `{port}` with the address of your Egon instance.

## Headers

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `token` | String | Yes | Authentication token sent in the `token` request header. |

## Request

Country context, `taxfnx` function `2`, and tax code to check.

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `par` | Object | Yes | Country context and tax-code validation function. |
| `par.iso2` | String | No | Country code, ISO 3166-1 alpha-2. One of `iso2` or `iso3` is **required**. |
| `par.iso3` | String | No | Country code, ISO 3166-1 alpha-3. One of `iso2` or `iso3` is **required**. |
| `par.taxfnx` | String | Yes | Tax-code configuration function. `2` Formal check and validation. Default value: `2` |
| `data` | Object | Yes | Input data to validate |
| `data.tax_code` | Object | Yes | Italian tax code to validate |
| `data.tax_code.cod_iso3` | String | No | Country code (ISO 3166-1 alpha-3) |
| `data.tax_code.cod_type` | String | No | Type of code |
| `data.tax_code.cod_description` | String | Yes | Italian tax code to check |

### Example request

```bash
curl -X POST "https://{host}:{port}/Egon/api/norm" \
  -H "token: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"par":{"iso3":"ITA","taxfnx":"2"},"data":{"tax_code":{"cod_iso3":"ITA","cod_type":"01110","cod_description":"RSSMRA93B19L781K"}}}'
```

## Response

Validated tax code, extraction verification quality indicator, and system status.

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `data` | Object | No | Normalized and enriched validation output data |
| `data.tax_code` | Object | No | Validated tax code details |
| `data.tax_code.cod_description` | String | No | Italian tax code |
| `quality` | Object | No | Validation quality indicators and score flags |
| `quality.tax_code` | Object | No | Quality indicator result (see https://documentation.egon.com/docs/quality-indicators) |
| `quality.tax_code.flag` | String | No | Quality flag |
| `quality.tax_code.code` | Number | No | Quality result code |
| `quality.tax_code.description` | String | No | Quality result description |
| `system` | Object | No | Request processing status. |
| `system.ret_code` | Number | No | Processing result code. 0 means no blocking error. |
| `system.des_ret_code` | String | No | Human-readable processing result. |

### Example responses

**HTTP 200: Valid response**

Tax code verified and found formally valid.

```json
{
  "data": {
    "tax_code": {
      "cod_description": "RSSMRA93B19L781K"
    }
  },
  "quality": {
    "tax_code": {
      "flag": "0",
      "code": 0,
      "description": "Ok"
    }
  },
  "system": {
    "ret_code": 0,
    "des_ret_code": "Ok"
  }
}
```

**HTTP 200: Missing par**

The request is missing the required par object.

```json
{
  "system": {
    "ret_code": 1,
    "des_ret_code": "par not found"
  }
}
```

**HTTP 200: Missing iso2 and iso3**

Iso2 or Iso3 field is missing.

```json
{
  "system": {
    "ret_code": 1,
    "des_ret_code": "iso2 or iso3 parameter not found"
  }
}
```

**HTTP 200: Invalid iso2**

The iso2 value is not valid.

```json
{
  "system": {
    "ret_code": 1,
    "des_ret_code": "iso2 not found"
  }
}
```

**HTTP 200: Invalid iso3**

The iso3 value is not valid.

```json
{
  "system": {
    "ret_code": 1,
    "des_ret_code": "iso3 not found"
  }
}
```

**HTTP 200: Missing data**

The request is missing the required data object.

```json
{
  "system": {
    "ret_code": 1,
    "des_ret_code": "data not found"
  }
}
```

**HTTP 200: Missing token**

Provide the required authentication token in the token request header.

```json
{
  "system": {
    "ret_code": 1,
    "des_ret_code": "token not found"
  }
}
```

**HTTP 200: Invalid token**

The supplied token is invalid, expired, or not authorized for this service.

```json
{
  "system": {
    "ret_code": 1,
    "des_ret_code": "token not valid"
  }
}
```