How to Create a GST Invoice in Singapore (2026 Guide)
30/05/2026SG
Issuing a compliant GST invoice in Singapore is a legal requirement for every GST-registered business. Get it wrong and your clients lose their right to claim input tax — and you risk penalties from the Inland Revenue Authority of Singapore (IRAS). This guide covers exactly what your invoices must include, when each format applies, and what the upcoming InvoiceNow mandate means for your business.
This article is for general informational purposes only and does not constitute tax or legal advice. Tax rules change — always verify current requirements directly with IRAS or a qualified tax professional before relying on this information for compliance purposes.
The Current GST Rate in Singapore
The standard GST rate is 9%, confirmed stable for 2026 and beyond. This followed a two-stage increase: 7% to 8% on 1 January 2023, then 8% to 9% on 1 January 2024. The Ministry of Finance has indicated no further increases are planned before 2030.
Source: IRAS GST Rate Guide
Do You Need to Register for GST?
Before issuing a GST invoice, confirm your registration status. IRAS applies two tests:
- Retrospective test: Your taxable turnover exceeded SGD 1 million at the end of any calendar year.
- Prospective test: You reasonably expect your taxable turnover to exceed SGD 1 million in the next 12 months.
Voluntary registration is available below this threshold, subject to a minimum two-year commitment.
Businesses that are not GST-registered must never charge GST or use the words "Tax Invoice" on their documents. Doing so is a statutory offence — the buyer cannot claim input tax, and the supplier faces fines of up to SGD 10,000 plus a 10% penalty on the overdue tax.
Source: IRAS — Registering for GST
Standard vs Simplified Tax Invoice: Which Format Applies?
The format you must use depends on the gross transaction value, inclusive of GST, measured against a threshold of SGD 1,000.
Standard Tax Invoice (transactions above SGD 1,000)
When a transaction exceeds SGD 1,000, you must issue a Standard Tax Invoice containing all eleven mandatory fields:
- The words "Tax Invoice" displayed prominently
- Your full legal business name and registered address
- Your GST Registration Number
- A unique, sequential invoice number
- The date of issue
- Your customer's name and address
- A description of the goods or services supplied
- The applicable GST rate (9% for standard-rated supplies)
- The total amount payable excluding GST
- The total GST payable, shown as a separate line
- The total amount payable including GST
The invoice must also separately state amounts for standard-rated, zero-rated, and exempt supplies where applicable. Using the words "Invoice", "Bill", or "Receipt" for transactions above SGD 1,000 does not satisfy IRAS requirements.
Simplified Tax Invoice (transactions of SGD 1,000 or below)
For lower-value transactions, a Simplified Tax Invoice reduces the administrative burden. Customer details and separate GST breakdowns are not required, but the document must include:
- Your legal name, address, and GST Registration Number
- A sequential invoice number and date
- A description of goods or services
- The total amount payable including GST
- The mandatory statement: "Price payable includes GST"
If a GST-registered customer requests a Standard Tax Invoice for a transaction under SGD 1,000, you are legally required to provide one within 30 days.
| Field | Standard (> SGD 1,000) | Simplified (≤ SGD 1,000) |
|---|---|---|
| "Tax Invoice" label | Required | Not required |
| Customer name and address | Required | Not required |
| GST shown separately | Required | Not required |
| "Price payable includes GST" | Not required | Required |
| GST Registration Number | Required | Required |
Source: IRAS — Invoicing Customers
How to Display Your GST Registration Number
Your GST Registration Number is an alphanumeric code issued by IRAS. For most companies incorporated through ACRA, it is identical to your Unique Entity Number (UEN) — for example, 200312345A. For older entities or sole proprietorships, you may have a separate GST number beginning with M (for example, M12345678).
Display it clearly on every tax invoice. Buyers can verify any supplier's registration status using the IRAS GST Registered Business Search.
GST Calculation and Rounding Rules
IRAS permits two calculation methods — apply one consistently across all invoices:
- Line-item method: Apply 9% GST to each individual line item, round each to the nearest cent, then sum.
- Aggregate method: Sum all pre-tax line items first, then apply 9% once to the total and round to the nearest cent.
For cash transactions, you may round the final gross amount to the nearest 5 cents. Minor rounding discrepancies do not require a GST F7 error correction form, provided your method is applied consistently.
For foreign currency invoices, convert three figures into SGD on the face of the invoice using an approved exchange rate: the pre-tax total, the GST amount, and the gross total.
Source: IRAS e-Tax Guide — GST Rate Change
The InvoiceNow Mandate: What's Changing
Singapore is moving toward mandatory e-invoicing through the InvoiceNow network, coordinated by IMDA and built on the global Peppol framework. Instead of PDF invoices, InvoiceNow transmits structured XML files directly between accounting systems in real time, with a copy sent automatically to IRAS.
The rollout is phased by business size and registration type:
| Deadline | Who Is Affected |
|---|---|
| 1 November 2025 | Newly incorporated companies registering voluntarily within 6 months of incorporation |
| 1 April 2026 | All new voluntary GST registrants |
| 1 April 2028 | New compulsory registrants and existing businesses with annual supplies ≤ SGD 200,000 |
| 1 April 2029 | Existing businesses with annual supplies ≤ SGD 1 million |
| 1 April 2030 | Existing businesses with annual supplies ≤ SGD 4 million |
| 1 April 2031 | All remaining registered businesses |
Government support is available: an SME transitional grant of up to SGD 1,000 and an early-adopter grant of up to SGD 5,000. Free InvoiceNow-ready solutions are also available for SMEs until March 2031.
Keep in mind that records — including tax invoices — must be retained for five years.
Sources: IRAS — GST InvoiceNow Requirement | IMDA — InvoiceNow
Getting Paid Faster: PayNow on Your Invoice
Singaporean businesses can embed a PayNow QR code directly on their invoices. Using a Dynamic SGQR code links your specific invoice number and amount to the payment, so clients pay instantly with no manual entry errors. PayNow Corporate fee waivers run until 31 December 2028, making it a cost-effective option for most businesses.
FAQ
What is the current GST rate in Singapore?
The standard GST rate is 9%, effective from 1 January 2024 and confirmed stable through at least 2030 by the Ministry of Finance.
Do I need to issue a standard or simplified tax invoice?
It depends on the gross transaction value inclusive of GST. Transactions above SGD 1,000 require a Standard Tax Invoice with eleven mandatory fields. Transactions of SGD 1,000 or below may use a Simplified Tax Invoice, provided it includes the statement "Price payable includes GST".
Can a non-GST-registered business charge GST?
No. Non-registered businesses are prohibited from charging or displaying GST and must never use the words "Tax Invoice". Doing so is a statutory offence under the Goods and Services Tax Act.
What is the InvoiceNow deadline for new voluntary GST registrants?
New voluntary GST registrants must adopt InvoiceNow as a legal condition of registration from 1 April 2026 onwards.
How long must I keep GST invoices?
IRAS requires all GST records, including tax invoices, to be retained for a minimum of five years.