I do not know where to find the Certification/Project No.

Please see form Sch IN-OCC. This form is used to report one of many reasons you can get a credit in Indiana.

Note Column C: "Column C Certification/ Project Number". It sounds like one or more of the entries in Column C is missing.

The "Certification/Project No" should be on the certificate or communication that you received from the state when you were authorized for this credit. As the state instructions say, "Enter the certification or project number you received from the authorizing entity. You can find this number in the certification letter you received from the authorizing entity or on your IN K-1."