Travelers should carry cash in three separate currencies because card payments are not accepted at border counters or desert rest stops: Jordanian Dinars (JOD) for Jordanian border fees and food, clean and unblemished US Dollar banknotes (USD) for Iraqi border payments, and Iraqi Dinars (IQD) for stops along the Iraqi highway.
For more: Crossing the Jordan-Iraq Border at Turaibil: Shared Taxis, Border Fees, and Road Conditions