> For the complete documentation index, see [llms.txt](https://docs.toomuchmedia.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.toomuchmedia.com/nats-admin/billers/further-reading/extra-biller-fields.md).

# Extra Biller Fields

*Article Topics:* [*Biller*](/getting-started/getting-started-with-billers.md)*,* [*Customization*](/getting-started/common-topics/customization.md)

Some billers offer hundreds, or even thousands, of modifiable options on their join form, which we refer to as "Nextra" features.

## Nextra Features

NATS lets you modify these extra features through a simple process, in order to take advantage of these options.

*Nextra* features can be used with NATS by simply adding the keyword *nextra* to any HTML name field, followed by your selected biller's shortname, and then the special value you want to edit, enclosed in brackets. Simply use the following format:

```
nextra[Biller Shortname][Special Value]
```

{% hint style="info" %}
**Please Note:** If necessary, you can find your biller's shortname through the [Billers Admin](/nats-admin/billers.md). Every biller shortname will be listed in the "Current Billers" table in the "Shortname" column.
{% endhint %}

## Usage Examples

For example, you can send the "date" special value to [CCBill](/getting-started/integrations/supported-billers/ccbill.md) by using any of the following examples:

* `<input type="hidden" name="nextra[CCBILL][date]" value="2006-06-11">`
* `<input type="text" name="nextra[CCBILL][date]">`
* `<textarea name="nextra[CCBILL][date]" cols="10" rows="10"></textarea>`

These types of actions can be performed with a variety of billers as well. For example, you can send the same special value (or *Nextra* value) to [NetBilling](/getting-started/integrations/supported-billers/netbilling.md) with this feature.

To do so, just add a *Nextra* command like the example provided below (or the examples provided above):

```
[NETBILLING][date]
```

For NetBilling and other gateway billers, this will need to be placed on the gateway\_join template instead of the join template.