Usually, your lawyer provides you with the property key when you close on your home. However, this is not required to complete the registration for the STAR credit.
You will need the following information to register for the STAR credit:
No. When applying for the NYS STAR Credit, the required answer is for whether or not you have a property key. Since you do not have yours, you would answer No to this question. I have attached a picture below for additional guidance.
Please make sure you are using the blue register link on the page Register for the STAR credit.