BYJU'S Exam Prep Coins are performance indicators and represent your expertise in a subject or topic. You can use coins for any BYJU'S Exam Prep Test Series or Online Classroom transaction. You can pay upto 25% of the transaction value using coins. The rest of the amount has to be paid using the available payment options. For example, If you have Rs.200 worth of coins and you want to purchase a Test Series costing Rs. 300, you can use Rs. 75 (25% of 300) from the coin balance and pay the remaining amount.