QuickBooks | 5 is the max, 4 should be enough

Software: Intuit QuickBooks accounting software

For users who crossover from Excel or other accounting software need to take note that the decimal places for the exchange rate is “fixed ” in QuickBooks.

For example, the USD to SGD the decimal places is 5.

QuickBooks USD exchange rate

And the decimal places for SGD to JPY is 6.

QuickBooks - JPY exchange rate

After crossover to QuickBooks, you may require to pass a home currency adjustment journal to adjust the base currency value of the foreign currency accounts such as Bank, Accounts Receivable and Accounts Payable so to balance up with the existing Balance Sheet report.

Since the Banks are using 4 decimal places, you may follow the banks using 4 decimal places for the USD transactions.