Default discount code or coupon

Is it possible to have a standard coupon already filled in for a period of time. Like an early bird discount. We have various discount codes and we are not calculating a reduced figure for early bird but asking people to fill in the discount code. By not having the early bird calcuated in advance this will avoid double discounts. 

My question. How can a I make a default discount code or coupon for everyone. They may change the discount code but it is automatically filled in when they register?

To create a coupon code, please follow this guide: https://www.jotform.com/help/233-How-to-Add-Coupon-Code-to-Payment-Forms

After that, you can add options to your payment forms by following this guide: https://www.jotform.com/help/225-How-to-Add-Options-to-Payment-Forms

Please try it and let us know if you have any questions.