Unrealized Gains and Losses

In case you have accounts AR and AP in different currencies than your local currency, let's assume your company currency is in THB in organization settings and one of your accounts, in chart of accounts, currency is in USD.

The supplier contact currency by default should be in USD and Account Payable in USD too.

When creating a new invoice, once you select a contact, the currency will be auto selected ( USD in this case) from the contacts Default Currency.

Currency Rate for the invoice is at the rate 36.10.

When you view the Journal Entry for the invoice after it is posted, we will see the Currency Amount in original amount, for the following example 500USD and Account Payable - USD in Credit is THB

At the end of a particular period (day/ month/year) ,once the exchange rate is changed the revalued amount AP or AR can be seen real time in the report Unrealized Gain and Losses.

Go to Accounting > Reports > All Reports > Unrealized Gain and Losses

Select Date from start of year or month Date to put the date at the end of year or end of month.
You can see Account Payable - USD in the first column, Balance corresponds to the original currency from the invoice.
Next column Balance 18,050 THB this amount from journal entry, based on currency at invoice.
Next column Balance (Revalued) amount is the original amount ,( invoice * exchange rate) based on currency setting in financial setting (500*35=17,500).
Unrealized Gain/Loss, 550 is the account payable amount in THB based on invoice minus the revalued amount, from currency setting (18,050-17,500).

When you view your Balance Sheet Report, by default Convert Currency is unchecked, meaning your Account Payable - USD will show the amount in THB exchange rate based on the invoice amount.

If you check the convert currency, the Account Payable - USD will show the revalued amount taken from the currency exchange rate.

In the Profit and Loss report if you check Convert Currency, the amount shown in Unrealized Currency Gain/Loss is the revalued amount. In the example amount 3,407.04 is the amount from total FX Exposure variance amount from sum of all the revaluation amount from Unrealized Gain/Loss

Note : By default in Profit and Loss report, Convert Currency is unchecked.