Pan card is mandatory for only cash transactions or credit transactions

My Query is Pan is mandatory or not from the following points. 1. Pan is mandatory for more than 2lakh of cash invoice of sale/purchase 2. When we raise the invoice on the customer on credit basis is morethan 2 lakhs 3. When the customer has given the outstanding amount is rupees morethan 2 lakhs Please give me suggestions on the above query for pan mandatory