How can I add an Extension number to the existing phone field?

I've built a B2B form for a client. The client has said we need to add an Ext. data field to the form? How do I do that?

Thanks,

Mark

There is no automatic way to include the extension, but we can use a workaround. 

1. On properties require country code:

2. Click the sublabels to change them into area code, phone number, extension:

3. On the form designer> css > click on the fields to adjust the width:

You can test and clone  the demo form: 

http://form.jotformpro.com/form/51055291083955? 

Let us know if we can assist you further.