GST rate in Singapore: 9% on quotes, invoices and credit notes

The GST rate in Singapore is 9%, and only a GST-registered business charges it. If you are registered, IRAS requires the price in any quote to the public to include GST. A quote that says “$100 + GST” is on IRAS’s list of unacceptable formats, and failing to quote prices correctly is an offence that can bring a fine of up to S$5,000.

That rule changes how a quote is built. Below are three illustrative examples at 9% (a S$2,400 job, a S$1,090 price that already includes GST, and a discount after invoicing), a test for which invoice to issue, and a quote footer to copy. The businesses and S$ amounts in our examples are invented and the arithmetic is ours; the $100, $109 and pen examples are IRAS’s own. The IRAS page behind each rule is linked beside it.

This is general information about IRAS’s published rules as rechecked on 17 October 2026, not tax advice.

What is the GST rate in Singapore, and who charges it?

IRAS’s current GST rates page says the rate is 9% and that GST-registered businesses must charge and account for it on all sales of goods and services in Singapore, unless the sale can be zero-rated or exempted. IRAS’s overview of GST treats exports and international services as zero-rated (our zero-rating guide covers the tests), and lists the sale and rental of unfurnished residential property and financial services (its example is the issue of a debt security) among exempt supplies. The rates page carries a “Last updated 13 June 2025” line, and the table of past rates on it, as we read it, stops at 8% for 2023, so we state no start date for 9%. Confirm the rate on the day you rely on it.

IRAS’s overview also says that only GST-registered businesses can charge and claim GST, and only from their effective date of registration, which IRAS’s responsibilities page says is stated in the approval letter. You must register when taxable turnover exceeds S$1 million, and may choose to register voluntarily if it does not; our guide to GST registration covers how the threshold works. IRAS’s invoicing page says GST-registered businesses must transmit invoice data to IRAS using InvoiceNow-Ready Solutions, with mandatory participation implemented in phases; our InvoiceNow planning guide covers the adoption plan and our summary of IRAS’s September 2026 FAQ what is sent.

How must a GST-registered business show GST on a quote?

IRAS’s displaying and quoting prices page says a GST-registered business must display and quote prices inclusive of GST to the public, naming “written or verbal quotes” alongside price tags, advertisements and website prices (the page shows “Last updated 25 September 2026”). It puts the fine at up to S$5,000, as does IRAS’s responsibilities page. Using IRAS’s own $100 and $109 examples, these formats are acceptable:

• “$109”, the GST-inclusive price on its own
• “$109 (inclusive of GST)”
• “$109 w/GST”
• “$109 w/GST ($100 w/o GST)”, where the inclusive price must be at least as prominent as the exclusive one

IRAS lists these as unacceptable:

• “$100 + GST”, “$100 + 9% GST” and “$100 + $9 GST”
• “$100 w/o GST ($109 w/GST)”, which IRAS labels a prominent GST-exclusive price
• the phrases “Prices stated are subject to GST”, “…exclusive of GST” and “…before GST” when the GST-inclusive price is not stated

IRAS also says that if you give a discount equal to the GST amount, you must not advertise “no GST”, because GST is still in the discounted price. Hotels and food and beverage businesses that impose a service charge have a separate exception.

One gap needs your judgement. IRAS words the rule as prices “to the public”, and the pages we read do not say whether a quote to one named, GST-registered company is treated differently. Our inference, not IRAS’s wording: the fourth format suits a business-to-business quote, because the buyer’s finance team gets the before-GST figure while the inclusive price stays prominent, and it is one of the formats IRAS lists as acceptable. If you quote only registered businesses and want to rely on a different reading, ask IRAS first.

How do you work out GST on a S$2,400 job?

Consider a fictional furniture workshop in Woodlands, GST-registered, which costs a built-in wardrobe and shelving job at S$2,400 before GST.

• GST: S$2,400 × 9% = S$216
• Price including GST: S$2,400 + S$216 = S$2,616

The quote reads “S$2,616.00 w/GST (S$2,400.00 w/o GST)”, IRAS’s fourth acceptable format. “S$2,400 + GST” does not show the final price the customer pays, which IRAS says you must show, and it is on IRAS’s unacceptable list. Our free GST calculator adds 9% to a price, takes it out of a GST-inclusive price or shows a multi-line invoice both ways, rounded to the cent.

With several lines, the total GST can differ slightly because of rounding. IRAS’s invoicing page allows either 9% on each line (before GST) then summed, or 9% on the sum of the lines, and says to apply the chosen method consistently. Its three-pen example, at $1.28 a pen before GST, totals $4.20 one way and $4.19 the other.

How do you back GST out of a price that already includes it?

Take a fictional two-person design studio with a fixed S$1,090 price for a website refresh, GST included. A price including GST is 109% of the price before GST, so the GST inside it is 9/109 of the inclusive price (IRAS calls 9/109 the tax fraction).

• GST: S$1,090 × 9/109 = S$90
• Price before GST: S$1,090 − S$90 = S$1,000
• Check: S$1,000 × 9% = S$90

The shortcut of S$1,090 × 9% gives S$98.10, overstating the GST by S$8.10, because it treats GST as 9% of an amount that already contains it.

IRAS’s bargaining example for retail prices uses the same fraction: GST on a $109 product sold for $90 is 9/109 × $90 = $7.43, because GST is based on the final price agreed with the customer. Our inference is that the same arithmetic applies to a negotiated service price: if the client negotiates S$1,090 down to S$981 before work starts, the GST is S$981 × 9/109 = S$81 and the price before GST is S$900.

What does a credit note look like when you discount after invoicing?

Return to the workshop’s S$2,400 job. Its customer is a GST-registered company, so the workshop issued a tax invoice: S$2,400 before GST, S$216 GST, S$2,616 payable. After installation the customer finds a misaligned shelf, and the workshop agrees to take S$300 off the price before GST.

IRAS’s invoicing page lists accepting goods or services at a reduced price because the contract terms are not fully met, and a discount given for a past transaction, among the situations in which a credit note is issued. Here the credit note shows:

• Amount credited, before GST: S$300.00
• GST credited at 9%: S$27.00
• Total credited, including GST: S$327.00
• What the customer owes after the credit, if it has not yet paid: S$2,616 − S$327 = S$2,289 (S$2,100 plus S$189 GST)

IRAS requires an identifying number and date, your name, address and GST registration number, the customer’s name and address, the reason for the credit, a description with quantity and amount, the total credited before tax, the rate and amount of tax credited, and the total including tax. The original tax invoice’s number and date should also be shown.

On the return, the adjustment goes into the GST F5 for the accounting period in which the credit note is issued: here the workshop reduces standard-rated supplies (Box 1) by S$300 and output tax due (Box 6) by S$27. A credit note that corrects a mistake in GST treatment can need a GST F7 instead. If the customer still does not pay, see our guide to chasing an unpaid invoice.

Which invoice do you issue: tax invoice, simplified tax invoice or receipt?

IRAS’s invoicing page sets out which document goes to which customer:

1. If your customer is not GST-registered, you may issue a serially printed receipt instead of a tax invoice, showing the date, your business name and GST registration number, the total payable including GST and the words “Price payable includes GST”.
2. If your customer is GST-registered, issue a tax invoice, in general within 30 days of the time of supply. The customer uses it to support its input tax claim.
3. If the total payable, including GST, does not exceed S$1,000, you may issue a simplified tax invoice instead of the full tax invoice.

The S$1,000 limit is measured on the amount including GST. Applied to the examples above:

• S$2,616, the S$2,400 job: above the limit, so a full tax invoice.
• S$1,090, the S$1,000-before-GST price: also above the limit. It looks as if it qualifies, but the test uses the inclusive amount.
• S$981, the negotiated price (S$900 plus S$81 GST): within the limit, so a simplified tax invoice is allowed.

A full tax invoice must contain:

• the words “Tax Invoice”
• your name and address, and your GST registration number
• the invoice date and an invoice identifying number
• the customer’s name and address
• a description of the goods and services
• the GST rate
• the total payable excluding GST, the total GST, and the total payable including GST

If the invoice also covers exempt, zero-rated or other supplies, the gross amount for each type must be stated separately. A simplified tax invoice needs only:

• your name, address and GST registration number
• the date of issue and an identifying number, such as the invoice number
• a description of the goods or services
• the total payable including GST
• a statement similar to “price payable includes GST”

IRAS says to keep tax invoices you issue and receive for at least five years.

What to check before a quote goes out

A reply that names a price already belongs on the approve-each-time list in our guide to approving enquiry replies. Add these checks for whoever approves it; more are in the sales topic.

• The price the customer sees first is the GST-inclusive price.
• Any before-GST figure sits beside it and is no more prominent.
• No “+ GST”, “subject to GST” or “before GST” wording stands alone.
• Price before GST × 1.09 equals the inclusive price, and inclusive price × 9/109 equals the GST.
• Zero-rated or exempt lines are separated from the 9% lines, so the quote can mirror the tax invoice, which must state the gross amount for each type of supply separately.
• Any discount shows as a lower final price, and a discount equal to the GST amount is never advertised as “no GST”.
• For a GST-registered customer, you have the name and address a tax invoice must show.

A footer for a GST-registered business, with the brackets replaced:

IRAS lists the GST registration number as a required detail on tax invoices, simplified tax invoices and receipts. Adding it to a quote, the “Price includes 9% GST” wording and the validity date are our suggestions, not IRAS requirements we found. Next step: run your last three quotes through the list and note whether each showed the GST-inclusive price first.

Common questions