You can add custom fields in Biller Genie to your payment pages for your customers.
Go to Tools > Custom Fields.
Click the Add a Custom Field button
Fill out the Custom Field Details (Name, Type, and Is Required)
Note: You can create 3 different types of custom fields
You can choose to make an input for these fields required or disabled.
Click Create Custom Field
This is how the custom fields appear on the Hosted Payment Page.
If you want to make it required that your custom fields be filled out every time a payment is made, you can do the following:
Go to Tools > Custom Fields
Click the Id of the custom field you want to make required
Switch Is Required to Yes
Click Edit to Save
Now any payments made on the account will require this custom field to be filled out.