Which credit card gives the highest cashback on online shopping?

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.

I've been using this card for over a year now. In my experience, the rewards are decent but the real value is in the lounge access and the milestone benefits. Make sure to read the fine print on the welcome benefit — most banks only credit it after the first transaction, not on approval.

I had the same dilemma. The way I decided was: list down my top 3 monthly spend categories, calculate the rewards on each card, and pick whichever gives the highest cashback on MY pattern. Generic 'best card' lists are useless for personal decisions.