Grab charges 0.8%, same as Nets, according to my friend who accepts Grabpay, as of March 2020.
For Nets vs Grab, it is not so much as to how much you charge. Mom and pop stores are usually by more elderly people, and they do not know how to use or trust technology. I recently used Grabpay at this hawker store, his phone somehow no notification on received payment (some issue with network or his phone), but my side says payment made. Grab refused to do anything and asked me to settle with the merchant myself as they claimed the payment has gone through. In the end, have to pay him cash (ie double pay) first, before I can go off. He did call me at night to say that he did receive the Grabpay money, so now I have to go back to get back my money (I don't think he knows how to refund from Grab app).
Not sure if this is a tie up for Grab and Nets, but when I look at his phone while he checks, he checks the Nets merchant app (ie 1 QR code for Nets, Grab etc). Or is he just not technologically savvy. And he mentioned that whole day, only me and someone else used Grabpay (both no payment received notification). So the usage rate is also very very low.
On the other hand, Nets is just a terminal. If something is not right, the money won't go through and is generally more foolproof, compared to Grab, especially those using their own phones and not technologically savvy. You want them to check phone for incoming payments, rather than printed black and white receipt.
