I think basically, the relationship between the taxis driver and
the pax must be a mutual one, as said by
some here, first, ask if Taxi uncle do not mind a $50,
and as a Taxi driver, even if he do not have changes for a
$50, he should inform the pax politely and the
solution can be done by deciding on making a change at a petrol
kiosk or 7 eleven, or coffe shops.
Unlike food centres or shops, a $50 can be changed easily as
many stalls are around, taxi do not have that luxury. If both the
pax and the TD have that mutual understanding, I believe that even
a $100 bill can be settle, and we can end up having a happy cabby
and a happy pax.
However pax should not take advantage in cases whereby the
fare is $12 and the pax said to have only a $100 note and a $10
notes resulting in the TD taking the $10 and forgo the $2. I had
met one of these kind before, Knn..give $1000 note, i also
change for you.