Thanks for the detailed explanation.
So for the below transactions am I right to say the following?
UBER BV BANGKOK TH THB700.00
Uber BKK = Quoted and charged in THB so no DCC or CBF
UBER BV VORDEN NLD SGD20.79
Uber SIN = Quoted in SGD but charged in NDL so there is CBF
EXPEDIA 18481046138 EXPEDIA SG SE SGD187.34
EXPEDIA COM SG 6568185635 SWE SGD707.92
Expedia.com.sg = Quoted in SGD but charged in SE (Sweden?) so there is CBF
VAYAMA COM READING GBR SGD317.52
Cheaptickets.sg = Quoted in SGD but charged in GBR so there is CBF