Swiggy HDFC credit card query

Its check only for merchant name, if u will order, he will get the cashback, simple.

Cashback depends on merchant name and category code. Account doesn't need to be same for eligibility of cashback. You can use any swiggy account and cashback will be credited accordingly.

Every card check merchant name and mcc code to provide cb/reward points , so yes you can order from your account

Your friend will get cashback regardless of in which account or device the card is used on swiggy