There was a post earlier comparing with a hypothetical ato bill to compare surcharge difference and points gained from both types of cards. It's really dependent on the card's points conversion to miles ratio.
Well, I just did my own calculations based on using Amex Plat card. Please correct me if I'm wrong.
Amex use on ATO bills
$1 = 0.5 MR pts
1.45% surcharge
e.g.: $10,000 bill
= 5000 MR
= $145 surcharge
therefore, 5000 MR = 5000 KF miles (1:1 ratio for amex plat)
--> 34.48 KF miles/$
note: should you consider tax deduction when calculation pts/$ ?
SQ F MEL-LHR flight
= $13,000 for flight this month
= 225250 KF miles (after 15% discount)
--> 17.32 KF miles/$
Based on these figures, am I right to continue using my amex plat to pay off ATO bills, if I had done the calculations correctly with the right conversions?
p.s. My only other card is Citi plat rewards card as I was unable to get the signature so had to get the missus to sign up for it. Don't know about my chances on getting another rewards card if I'm self employed anytime soon.