Can I ask for last 4-digits of credit card number in form?

Hi, 

I would like to setup a form, and integrate it with the built in Authorize.net widget to collect payment.

I would also like the client to sign that form and agree to our terms.  Basically, the client would need to agree that they authorize the charge.  This protects from potential issues of chargebacks, etc because we have the clients signature.

I know it is a violation to ask for full credit card details in the form, but can we ask them to enter their last 4 digits of the card they are using for payment, as part of agreeing to the terms?

The question would go something like:

"Please enter your last 4 digits of the card you are using to agree that Company Name will be charging $100 for (whatever service)"

Is this ok to do?

Unfortunately, that is not possible. It is against our terms of use to collect credit card information on plain text fields, even last four digits. 

I would suggest you ask your users to provide you last four digits over the phone or via email. 

You can also add signature field to your form and ask your users to sign that they agree to be charged.  

E-Signature

Smooth Signature

How to Add a Widget to your Form?

If you want to have payment fields inside of your form you have to use one of JotForm payment tools. 

Inside of this articles you can find out more about payment tools and how to set payment form:

http://www.jotform.com/help/47-Order-Form-Basics 

http://apps.jotform.com/category/payment_processing 

http://www.jotform.com/help/165-Setting-Up-Your-First-Order-Form 

http://www.jotform.com/help/292-How-to-Enable-Payment-Authorization 

Hope this will help. Let us know if you need further assistance.