Which credit card gives the highest cashback on online shopping?

Credit score impact: each hard inquiry (which happens on card application) drops your score by 5-15 points temporarily. Applying for 3 cards in 2 months is fine IF you get all 3 approved. If 2 get rejected, you've taken a hit with nothing to show for it. Apply smart, not fast.

On the add-on card: yes, the primary cardholder is fully liable for all spends on the add-on. There is no separate credit limit or statement. So only issue it to someone you trust absolutely — spouse, parents. Not friends, not siblings you have money disputes with.

On the annual fee — most premium cards waive it if you spend ₹1.5L to ₹3L in the previous year. Wallet loads (Paytm, Amazon Pay balance) usually DON'T count. But utilities, fuel, and grocery do. Spend pattern matters more than absolute number.