Why was I charged brokerage on delivery trades?

You may have been charged brokerage because your trades qualified as intraday transactions, even though you used Longterm (CNC) for delivery trading. Zerodha does not charge brokerage for genuine delivery-based trades. However, you may be charged intraday brokerage of 0.03% or ₹20 (whichever is lower) per executed order in these situations:

When do intraday charges apply

• The same share is bought and sold in one trading session using Longterm (CNC) product type. For example, 10 shares of ITC were bought at 10 AM and sold at 2 PM. In this case, intraday charges would be applicable as the shares were bought and sold on the same day.
  
• Shares held in the demat account are sold and bought back on the same day using CNC. For example, there are 100 Infosys shares held in the demat account. At 11 AM, 50 shares were sold, and later at 1 PM, 25 shares were bought back. Intraday charges will be applicable for both orders, regardless of the quantity bought back.