Specify the currency conversion rate
GST register trader who supplies goods in foreign currency instead of Singapore dollar has to indicate the Singapore dollar equivalent GST amount on the invoice. The buyer who received the Bill has to record it based on the exchange rate stated in the Bill instead of the in-house exchange rate set in the accounting systems.
Assuming your in-house exchange rate is 1SGD:0.7400USD but received a bill of USD10,000 with a GST of USD700 at an exchange rate of 1SGD:0.7431USD. In this case, you should record the Purchase Invoice (Bill) into MoneyWorks at an exchange of 1SGD:0.7431USD instead of 1SGD:0.7400USD. The GST amount recorded should be SGD942 instead of SGD945.95.
Below are the double entry of a Purchase Invoice at a different exchange rate.
Exchange Rate is 1SGD:0.7400USD
Debit Expense 10,000 Credit USD Accounts Payable 10,700 Debit Expense 3,513.51 Credit USD Accounts Payable Delta 3,759.46 Debit GST Paid (Input) 945.95
Exchange Rate is 1SGD:0.7431USD
Debit Expense 10,000 Credit USD Accounts Payable 10,700 Debit Expense 3,457.14 Credit USD Accounts Payable Delta 3,759.46 Debit GST Paid (Input) 942.00
By default, a foreign currency transaction picks up the system exchange rate; to change it, click the 'Exchange Rate' button on top of the transaction window, follow by unchecked the 'Use system rate at posting time' checkbox in the Currency Rate wizard, and change the exchange rate accordingly. This change allows the system to use the exchange rate you set in the transaction instead of using the system rate at the posting time.
MoneyWorks will adjust the outstanding Purchase Invoice, the foreign currency accounts payable account, to the unrealised exchange gain/loss account when there is a change in month-end exchange rate.
You should discuss the GST matter with your accountant or find out more from IRAS.