Hi there, manceps,

I understand how you want the use the 8 decimals for the exchange rate. 

The Currency & Exchange Rates list is updated to display the new currency with the most recent rate from Markit. Hence, QuickBooks Online uses 7 decimals. See the exchange rate and how it's calculated in QuickBooks Online for more details.

To  ensure you have accurate balance when you reconcile the account, you'll need to create a dummy bank account. This will help facilitate the movement between 2 different foreign currencies.

1. Select the Gear icon, then select Chart of Accounts
2. Select New
3. Under Account Type column, select Cash and cash equivalent. Under Detail Type column, select Cash on hand. And under Name column, type in Dummy Bank
4. Before saving and closing, make sure that it is in the home currency (which is SGD in this case).

After that, record the payment of the foreign invoice. In the Receive Payment module, set the Deposit To field to Dummy Bank Before saving the transaction, take note of the home currency (SGD) amount displayed at the bottom right.

For example, you've received USD 1000 payment for the invoice and this gives me SGD 1300. You'll have to transfer this SGD 1,300 from Dummy Bank to the EUR bank account. Here's how:

1. Click + New, then choose Transfer.
2. Under Transfer Funds From column, select Dummy Bank from the drop-down arrow.
3. Under Transfer Funds To, select EUR Bank from the drop-down arrow.
4. Under Currency column, select SGD from the drop-down arrow.
5. Under Transfer amount column, type in 1300
6. Under Exchange rate, the exchange rate will automatically appear which is 1.625 in this case.
7. You can manually change the rate.

To pay for this USD invoice, the customer paid EUR 800. To get EUR 800 from SGD 1300, we divide 1300 with 800 to get 1.625 as the exchange rate.

Let me know if you need additional information by commenting below. I'm always right here to help.