In order to ensure smooth transactions in the securities market, regulator Security Exchange Board Of India (SEBI) on Wednesday informed all investors that they must link their Permanent Account Number (PAN) to Aadhaar by March 31. Any non-compliance in this regard would mean non-KYC compliant which could further create restrictions on securities and other transactions until the PAN and Aadhar are linked, the markets regulator said in a statement.