You can grab your Kavach Number through the BSNL Self Care app or website, or by calling customer care (dial 1800 180 1503 or 1500 and press 9).
Each Kavach number is temporary and may expire and may require regeneration for future recharges and hides your actual phone number from retailers, keeping things smooth and private.

Kavach is all about tackling privacy worries (like unwanted calls or creepy messages) that come from sharing your real number at stores, especially in places where digital payments aren't common.
No extra SIMs are required; any charges, if applicable, have not been specified—just a simple way to keep your info safe while topping up.