If you owe Indiana state taxes, a Post Filing Coupon (PFC) will print with your return. This form must accompany any payment you make to the Indiana Department of Revenue (if you expect to receive a refund, there is nothing to mail and the PFC will not print) .
If you are filing the return electronically, you will be able to print the voucher during the e-filing steps. You will come to a screen titled Indiana E-Filing Step - Form IT-8453-OL/PFC where you can print the voucher. If you print or view the instructions from the screen titled E-filing - Print Indiana E-file Instructions, there is additional information regarding paying the balance due to Indiana.
There will be instructions above the voucher section when you print the post filing coupon. These instructions will provide you with the address and payment options for completing your balance due.