### 400 Bad Request

You may receive a `400 Bad Request` if:‌

#### There are issues in the body of your request

- A required field is missing.

```json
"information": {
     "addresses": ["This field is required."]
}
```

**How to fix this issue**

Add all the required fields to the body of your request.

- You used the wrong format or data type for a field.

```json
"city": ["Not a valid string."]
```

**How to fix this issue**

Format all your fields according to their [data type](https://www.w3schools.com/js/js_json_datatypes.asp).

#### There's an issue with your account

- Your account isn't configured to run this check or your account does not have payment configured.

```json
"request_equifax": ["Account not configured to \"request_equifax\". Please contact support@certn.co to update your plan."]
```

**How to fix this issue**

[Contact our support team](https://docs.certn.co/api/contact#api) to have your account configured for this check or to confirm that your payment method is correctly configured.

For a demo account, use this [payment method](https://docs.certn.co/api/start/demo-account).

#### Something is preventing your request from completing

- You tried to generate a report, but the application is still processing.

```json
"non_field_errors": ["Cannot generate report for incomplete hr applicant."]
or
"non_field_errors": ["Cannot generate report for incomplete applicant."]
```

**How to fix this issue**

Wait for the application's `status` field to show `Returned` before generating the final report.

- You requested a check with a `min` and a `max` but set your `min` value to a number greater than your `max` value.

```json
"non_field_errors": ["employer_references_max must be greater than employer_references_min."]
```

**How to fix this issue**

Edit the request's check settings to make sure that any `min` values are less than or equal to the corresponding `max` values.

### 401 Unauthorized

You may receive a `401 Unauthorized` if:‌

#### Your authorization header is missing or incorrect

- You sent your request without an authorization header.

```json
"detail": "Authentication credentials were not provided."
```

- You sent your request with an authorization header, but without an API Key.

- You provided an incorrect API key in the header of your request.

```json
"detail": "Invalid token."
```

**How to fix this issue**

Add an [authorization header](https://docs.certn.co/api/guides/use-the-api/authorization-header) to your request and make sure it includes your API Key.

### 403 Forbidden

You may receive a `403 Forbidden` if:

#### You don't have permission to make this request

- You sent your request to an endpoint you don't have access to.

```json
"detail": "You do not have permission to perform this action."
```

**How to fix this issue**

Use the URL that corresponds to your industry and make sure you're authorized to access this endpoint.

### 404 Not Found

You may receive a `404 Not Found` if:‌

#### The resource you called doesn't exist

- You sent a request to retrieve all your applications, but the page number you provided doesn't exist.

```json
"detail": "Invalid page."
```

**How to fix this issue**

Make sure the page number you entered is a valid integer and within the bounds of your expected results.

- You sent a request to retrieve an application or a report, but the application ID you provided couldn't be found.

```json
"detail": "Not Found."
```

- You sent a request to retrieve an application or a report, but the application ID you provided is a string of letters.

```json
"HTML Page" NOT FOUND
```

**How to fix this issue**

Add your [application ID](https://docs.certn.co/api/start/demo-account/retrieve-results#send-the-request) to the URL and make sure it's in the proper format.

- You sent a request to retrieve questionnaire reference templates for a team, but the team ID you provided couldn't be found.

```json
"detail": "Not Found."
```

- You sent a request to retrieve questionnaire reference templates for a team, but the team ID you provided is a string of letters.

```json
"HTML Page" NOT FOUND
```

**How to fix this issue**

Add your team ID to the URL and make sure it's in the proper format.

### 500 Internal Server Error

You may receive a `500 Internal Server Error` if:‌

#### You sent something we didn't expect

- Some fields in your request are using the wrong data type.

```json
"HTML Page" Server Error (500)
```

**How to fix this issue**

Format all your fields according to their [data type](https://www.w3schools.com/js/js_json_datatypes.asp). Most fields in our API take strings, while [request flags](https://docs.certn.co/api/api-reference/resources/application-parameters/request-flags) take booleans.