GST GUIDE · UPDATED JUNE 2026
GST InvoiceNow requirements for Singapore SMEs
All GST-registered businesses are moving toward structured invoice-data submission through InvoiceNow. Here is when your phase begins, what IRAS expects, and how to prepare without disrupting billing or GST filing.
ROLLOUT TIMELINE
When does your business have to comply?
Existing registrants use total annual supplies reported in Box 4 across prescribed accounting periods ending in calendar year 2025—not revenue from the latest financial statements.
Companies incorporated within six months of applying for voluntary GST registration.
Every business applying for voluntary GST registration, regardless of incorporation date or business structure.
New compulsory GST registrants, plus existing GST-registered businesses with 2025 total annual supplies of $200,000 or less.
Existing GST-registered businesses with 2025 total annual supplies of $1 million or less.
Existing GST-registered businesses with 2025 total annual supplies of $4 million or less.
Existing GST-registered businesses with 2025 total annual supplies above $4 million.
The quick SME test.
Applying voluntarily now?
You are already in scope.
All applications for voluntary GST registration made from 1 April 2026 must meet the requirement.
Already GST-registered?
Check 2025 Box 4.
Your total annual supplies determine whether your date is in 2028, 2029, 2030 or 2031.
Compulsory registration ahead?
Watch 1 April 2028.
Businesses applying for compulsory GST registration from that date enter the requirement immediately.
DATA SCOPE
What goes to IRAS—and what does not.
Transmit
- Standard-rated supplies
- Zero-rated supplies
- Exempt supplies
- Standard-rated purchases
- Zero-rated purchases
Excluded
- Transactions treated as supplies or purchases only for GST reporting, without an underlying supply or purchase
- Reverse-charge transactions
- Exempt financial services and exchange or loan of digital payment tokens
- Import permits for imported goods
Relevant documents include tax invoices, simplified tax invoices, sales invoices, serially numbered receipts, debit notes and credit notes. IRAS permits aggregation in specified cases such as point-of-sale supplies, simplified tax invoices and petty-cash purchases.
PREPARATION PLAN
Six steps to become InvoiceNow-ready.
Confirm your implementation date
Check whether you are a new voluntary or compulsory registrant. Existing registrants should use total annual supplies reported in Box 4 across prescribed accounting periods ending in calendar year 2025.
Review the current system
Ask your accounting or finance software provider whether your product and plan are on IMDA’s list of accredited InvoiceNow-Ready Solutions.
Register on the network
Work with the solution or Access Point provider to register the business in the SG Peppol Directory using its UEN and obtain a Peppol ID.
Enable IRAS transmission
Activate the GST InvoiceNow submission feature. Merely being able to send an e-invoice does not necessarily mean transmission to IRAS is enabled.
Map and test the data
Review tax codes, invoice fields, purchase workflows, credit notes, point-of-sale aggregation and acknowledgements before relying on the live process.
Set the filing cut-off
Build a review process so required invoice data reaches IRAS by the earlier of the GST return filing date or that return’s filing deadline.
Give the transition enough runway.
IRAS advises businesses with in-house enterprise systems to allow roughly 3 to 12 months for connection. Even an off-the-shelf setup needs time for Peppol registration, configuration, tax-code mapping, staff training and a clean test cycle. Start before the final GST period preceding your mandatory date.
Support for SMEs
Free-of-charge InvoiceNow-Ready solution packages are planned through March 2031, and eligible SMEs may receive up to $1,000 through the GST InvoiceNow Transition Grant. Check current IMDA eligibility, claim windows and provider terms before committing.
Common questions.
Is InvoiceNow already mandatory for SMEs?
It is already mandatory for businesses applying for voluntary GST registration from 1 April 2026, and for certain newly incorporated voluntary registrants since 1 November 2025. Existing GST-registered SMEs phase in from 1 April 2028 onward according to their 2025 total annual supplies.
Is a PDF invoice sent by email an InvoiceNow invoice?
No. InvoiceNow uses structured invoice data transmitted through Singapore’s Peppol-based network. A PDF may still be shared as a human-readable document, but emailing a PDF alone does not meet the GST InvoiceNow transmission requirement.
Must my customer also use InvoiceNow?
The GST InvoiceNow requirement concerns transmitting relevant invoice data to IRAS through an InvoiceNow-Ready Solution. Your data-submission obligation can still apply when the customer is not receiving invoices through InvoiceNow.
What is the deadline for transmitting invoice data to IRAS?
Required invoice data must be transmitted by the earlier of the date you file the relevant GST return or the filing due date for that return.
How do existing GST businesses determine their rollout phase?
Use total annual supplies reported in Box 4 of GST returns for prescribed accounting periods ending in calendar year 2025. This includes standard-rated, zero-rated and exempt supplies.
Is financial support available to SMEs?
Government support includes free-of-charge InvoiceNow-Ready solution packages and a GST InvoiceNow Transition Grant of up to $1,000 for eligible SMEs. Check current IMDA terms before applying or committing to a provider.
Official sources
Rollout details can change. These primary sources were checked on 27 June 2026.
Keep the GST filing date in view.
Invoice data must arrive by the earlier of filing or the return deadline. See those dates alongside your other 2026 obligations.
View the compliance calendarThis guide provides general information, not tax, legal or systems advice. Confirm your implementation date and technical requirements with IRAS, IMDA and your accredited solution provider.