Singapore's GST system is administered by the Inland Revenue Authority of Singapore (IRAS). For freelancers and small businesses, GST registration is typically only required above the S$1 million threshold — but understanding when invoices need to comply with tax invoice requirements is important for both registered and non-registered businesses.
GST registration: the S$1 million threshold
You must register for GST if your taxable turnover exceeds S$1 million in the past 12 months or if you expect it to exceed S$1 million in the next 12 months. This is a much higher threshold than most comparable countries, meaning the majority of Singapore freelancers and sole proprietors won't need to register.
Voluntary GST registration is permitted below the threshold. Benefits include being able to claim input tax credits on your business purchases — useful if you have significant business expenses.
Current GST rate: 9%
Singapore's GST rate is 9% as of January 1, 2024 (increased from 8% in 2023 and 7% before that). This rate applies to most supplies of goods and services in Singapore.
Zero-rated supplies (0% GST) include international services and goods exported from Singapore. Exempt supplies (outside the GST system entirely) include the sale and lease of residential properties and financial services.
What is a tax invoice in Singapore?
A Singapore tax invoice is a document issued by a GST-registered business that allows the recipient to claim input tax credits with IRAS. If you're GST-registered, you must issue a tax invoice for every taxable supply you make to another GST-registered customer.
What must appear on a Singapore tax invoice
IRAS requires the following fields on a full tax invoice:
- The words "Tax Invoice" clearly stated
- Your name, address, and GST registration number
- An identifying number (invoice number) — unique and sequential
- Date of issue
- Your customer's name and address
- Description of goods or services supplied
- Quantity and unit price of each item
- Discount (if any)
- Total amount payable excluding GST
- Total GST chargeable
- Total amount payable including GST
Simplified tax invoice: For taxable supplies of S$1,000 or less (GST inclusive), you may issue a simplified tax invoice. This requires your name, GST number, invoice date, description, and total amount — but does not need to show the customer's details or a breakdown of GST vs total.
Invoices for non-GST registered businesses
If you're below the S$1 million threshold and not registered for GST, you issue standard invoices — not tax invoices. You must not charge GST or use the words "Tax Invoice". Your invoices should still be professional and include:
- Your name and UEN (Unique Entity Number) or NRIC
- Invoice date and number
- Description of services
- Total amount
- Payment terms and bank details
UEN: your business identifier
Every Singapore business entity (registered with ACRA) has a Unique Entity Number (UEN). Sole proprietors and partnerships also have a UEN. Include your UEN on all invoices — it identifies your business and is expected by clients for their own record-keeping. For individuals, your NRIC/FIN serves as identification.
Credit notes and debit notes
If you need to adjust an invoice (e.g. for a returned service, discount, or error), issue a credit note or debit note rather than cancelling the original invoice. Credit notes reduce the original supply and must reference the original tax invoice number. Keep both documents on file.
GST registration number format
Your GST registration number is the same as your UEN, formatted as a 9 or 10-character alphanumeric code. For companies: last 2 digits of year + 7-digit number + letter (e.g. 201234567K). For sole proprietors with an NRIC: it will follow a different pattern. Display it clearly on all tax invoices.
Record-keeping requirements
IRAS requires businesses to retain GST records for 5 years from the end of the relevant accounting period. Digital records are acceptable. Records must be maintained in English or, if in another language, translated on request.
GST returns: quarterly filing
GST-registered businesses in Singapore file GST returns quarterly (or monthly for large businesses). Returns are filed electronically via myTax Portal. You report output tax (GST collected on sales) and input tax (GST paid on purchases) — the difference is what you pay to or claim back from IRAS.
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