Can I issue a tax invoice in USD in Singapore?

Yes, but the total before GST, the GST and the total including GST must also be shown in SGD.

Which exchange rate do I use for GST in Singapore?

A rate from an accepted source, such as MAS or a local bank, for the time of supply, used consistently.

Does a Japanese invoice in dollars need yen amounts?

The consumption tax for each rate must be in yen. Everything else may stay in the foreign currency.

What rate applies to a credit note on a foreign-currency invoice?

In Singapore, the original invoice's rate, or for a GST-registered customer the current rate if you apply it consistently. easySales uses the invoice's rate.

Do exchange gains and losses go in the Singapore GST return?

Net realised exchange gains or losses are reported as exempt supplies in Box 3.

Can I change the rate after issuing?

No. Correct the invoice with a credit note and issue a new one. See Fixing mistakes.

Foreign-currency invoices

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You can bill a customer in their own currency, but your tax return is in yours. Tax law therefore asks for the tax, and sometimes the totals, to be converted into the local currency at an accepted rate. This page sets out what each country asks. It is general information, not tax or legal advice: check the sources at the end or ask your accountant before you rely on it.

In short

Country	What must be in local currency	Rate
Singapore	Total before GST, the GST and the total including GST, in SGD	An approved source, such as MAS or a local bank, used consistently
Malaysia	Amounts on a service tax invoice, also in MYR	The selling rate in Malaysia when the service is provided
Japan	The consumption tax for each rate, in yen	As for income or corporate tax; if that is impractical, a reasonable method used consistently
New Zealand	The amounts for GST, in NZD at the time of supply	The buy rate of an approved bank or bureau de change
Australia	The value of the sale for GST, in AUD	Your chosen rate source, used consistently

Country by country

Singapore

Amounts on a tax invoice in a foreign currency must also be shown in Singapore dollars: the total before GST, the total GST and the total including GST. The rate is the day’s rate for the time of supply or a good approximation of it, from a source IRAS accepts without approval, such as the Monetary Authority of Singapore (MAS), a local bank or a reputable news agency. The rate you use is updated at least every three months and used consistently for at least one year from the end of the accounting period in which you first used it. The SGD amount of GST on your tax invoice is what your customer claims as input tax. For a credit note on a foreign-currency invoice, use the original rate; for a GST-registered customer you may use the rate of the day instead, as long as you apply your choice consistently.

Hong Kong

There is no sales tax, so no rule on showing amounts in Hong Kong dollars.

Australia

The value of a taxable supply is expressed in Australian dollars, and foreign-currency payment is converted as the Commissioner determines. Under that determination you divide the foreign-currency amount by your chosen exchange rate, expressed in units of foreign currency per A$1 — for example the Reserve Bank of Australia’s 4 pm rate, a published rate of a foreign exchange organisation, or a rate agreed with the customer — and use it consistently. On the accruals basis the conversion day is the earlier of the day you receive payment or the transaction or invoice date you have chosen.

New Zealand

All amounts for GST are expressed in New Zealand currency as at the time of supply. Inland Revenue says to convert at the exchange rate for the date of the time of supply, and a public ruling names the buy rate of an approved bank or bureau de change. A buyer who claims GST needs taxable supply information in New Zealand currency.

Japan

Every item on a qualified invoice may be in a foreign language or currency except one: the consumption tax for each rate must be stated in yen. The rate follows income and corporate tax practice. If that is impractical when you issue the invoice, a reasonable method used consistently is accepted, such as the rate on the day you issue the invoice or the settlement day. The tax in the foreign currency is not rounded before conversion; the yen tax is rounded once.

Malaysia and Brunei

On a Malaysian service tax invoice, any amount in a currency other than ringgit is also shown in ringgit at the selling rate prevailing in Malaysia when the service is provided. Brunei has no GST or VAT.

In easySales

Choose the invoice’s Currency; easySales proposes an automatic rate and shows its source and date. Select Change rate to type your own. See Invoice exchange rate.
When the invoice is issued, its rate is fixed for the PDF, the receivables and the statement.
For a GST-registered Singapore company, a foreign-currency invoice that charges GST prints a For Singapore GST Purpose Only block with its amounts in SGD; a Malaysian company registered for SST gets a For Malaysia SST Purpose Only block in MYR. See Invoice PDF.
A credit note converts at the rate of the invoice it credits. See Currency and rates.

Examples

Lim & Co, GST-registered in Singapore, invoices a GST-registered client USD 2,000.00 plus GST of USD 180.00. The MAS rate on the invoice date is 1 USD = 1.3500 SGD. The tax invoice shows:

	USD	SGD
Total before GST	2,000.00	2,700.00
GST 9%	180.00	243.00
Total including GST	2,180.00	2,943.00

Lim & Co reports SGD 243.00 as output tax, and its client claims SGD 243.00 as input tax.

Common questions

Can I issue a tax invoice in USD in Singapore? Yes, but the total before GST, the GST and the total including GST must also be shown in SGD.
Which exchange rate do I use for GST in Singapore? A rate from an accepted source, such as MAS or a local bank, for the time of supply, used consistently.
Does a Japanese invoice in dollars need yen amounts? The consumption tax for each rate must be in yen. Everything else may stay in the foreign currency.
What rate applies to a credit note on a foreign-currency invoice? In Singapore, the original invoice’s rate, or for a GST-registered customer the current rate if you apply it consistently. easySales uses the invoice’s rate.
Do exchange gains and losses go in the Singapore GST return? Net realised exchange gains or losses are reported as exempt supplies in Box 3.
Can I change the rate after issuing? No. Correct the invoice with a credit note and issue a new one. See Fixing mistakes.

Sources

Last checked: 21 October 2026.