Can I assign a unique Member ID to every new registrant?

I want to take memberships online and I'd love to be able to assign the individual a member number automatically when they sign up. Something with a letter and number that goes up with each new membership. So for example O11, O12, O13, etc. (A system or starting number that I assign.)

I don't need people to have an account or be able to login or anything like that. I just want to assign their member number as soon as they pay so that I can reference that number in their "Welcome letter" sent out the next day or something and so that I can import their member number into our HighRise account along with their other details. 

Is this possible?

A resounding yes. It's the Unique ID widget. Here's how you can set it up in your form:

https://www.jotform.com/help/79-How-to-Add-Custom-Unique-IDs-to-your-Form-Submissions 

A "resounding yes" is such a nice thing to hear! That article looks like just what I need! I will explore it further. Thanks!

You're welcome :) Please contact us again if you need help with the Unique ID widget.

We also have the following widget that would let you record a unique identifier for submissions:

https://widgets.jotform.com/widget/random_value_generator

The only thing on this widget is the value which is random, not a series.