Can data from a previously submitted form determine which form to use next?

Example:

Customer enters their order number and clicks submit.  If the order number was previously submitted in another form, then redirect to formB.  If the order number was not previously submitted in another form, then redirect for formA.

You can redirect forms to a different form or URL depending on the users selection or answer in the form but unfortunately, there's no way to check or create a condition that checks the existing data from the other form unless you will write a custom script using Jotform API that perform such functionality. I'm afraid it will be a little complicated to do so.

So for now, here's how to redirect users to a different form or URL depending on their answer.

Guide: http://www.jotform.com/help/317-Configuring-Change-Thank-You-URL-after-submission-condition

If you need further questions, let us know.