If your business is GST-registered in Singapore, you will have to send invoice data to IRAS through the InvoiceNow network. IRAS is notifying businesses registered before 2026 of their individual deadline through the middle of this year. If you registered voluntarily on or after 1 April 2026, the requirement already applies to you.
The full rollout runs to April 2031. Your date depends on when and how you registered for GST, and on your total annual supplies for 2025.
The phases
New registrants
| From | Who |
|---|---|
| 1 Nov 2025 | Companies that voluntarily registered for GST within six months of incorporation |
| 1 Apr 2026 | All new voluntary GST registrants, regardless of incorporation date or business structure |
| 1 Apr 2028 | All new compulsory GST registrants |
Existing GST-registered businesses, by total annual supplies in 2025
| From | Total annual supplies |
|---|---|
| 1 Apr 2028 | Up to S$200,000 |
| 1 Apr 2029 | Up to S$1 million |
| 1 Apr 2030 | Up to S$4 million |
| 1 Apr 2031 | Remaining businesses |
“Total annual supplies” means standard-rated, zero-rated and exempt supplies across all prescribed accounting periods ending in calendar year 2025.
If you are registering voluntarily now, this is not a future problem. Since 1 April 2026, being on an InvoiceNow-Ready Solution is effectively part of voluntary GST registration.
How to find your date
IRAS publishes an Implementation Date Calculator — a spreadsheet where you enter your registration details and 2025 supplies and it returns your wave. It is on the IRAS GST InvoiceNow Requirement page.
IRAS is also writing to businesses registered before 2026 with their specific date during 2026. You are expected to self-assess in the meantime rather than wait for the letter.
What InvoiceNow actually is
InvoiceNow is Singapore's national e-invoicing network, run by IMDA since 2019 and built on the international Peppol standard.
It is not a portal you log into, and it is not emailing a PDF. Invoices move as structured data between accredited access points, and under the GST requirement IRAS receives that data through what IRAS calls the five-corner model — supplier, supplier's access point, buyer's access point, buyer, and IRAS.
Practically: your accounting or invoicing system has to be InvoiceNow-ready — either an IMDA-accredited InvoiceNow-Ready Solution, or connected through an accredited access point. See our guide on how to choose an InvoiceNow-Ready Solution.
Not everything is in scope. IRAS excludes several transaction types, including supplies made through point-of-sale systems, supplies where a simplified tax invoice or serially numbered receipt is issued, and petty cash purchases such as staff claims. The e-Tax Guide has the full list — check it against how your business actually invoices before assuming everything must go through the network.
What you need to do
- 1Find your date. Use the IRAS calculator, or wait for your notification if you were registered before 2026. Do not assume you are in the last wave.
- 2Check your current system. Ask your accounting or invoicing provider one question: are you InvoiceNow-ready, and if not, when will you be? Many older desktop packages will not be.
- 3Claim the grant. The Government has announced transitional funding to offset onboarding — up to S$1,000 for SMEs and up to S$5,000 for larger businesses. IMDA also lists InvoiceNow-Ready Solutions available free to SMEs until March 2031.
- 4Onboard before your wave. Early adoption is encouraged and there is a practical reason for it: around 90,000 more businesses are expected onto the network, and support queues will not get shorter closer to each deadline.
- 5Keep your records. InvoiceNow does not replace your obligation to keep proper GST records and supporting documents.
Where Critical Mass Cloud fits
Critical Mass Cloud handles InvoiceNow as part of its accounting module, alongside GST returns, HR and payroll with CPF and IRAS filing, and e-signatures — one Singapore-native platform rather than several stitched together.
Being straight about it: if all you need is e-invoicing, you do not need to pay for it. IMDA lists InvoiceNow-Ready Solutions free for SMEs until March 2031, and using one is a perfectly good answer to this requirement.
Critical Mass Cloud is worth looking at if the invoicing sits alongside payroll, CPF, IR8A, GST returns and signed documents — and you would rather those were one system with one login than four that need reconciling.
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I am not GST-registered. Does this affect me?
No. The requirement applies to GST-registered businesses. If you register later, it will apply from the date for your category.
What happens if I miss my date?
For voluntary registrants, InvoiceNow readiness is effectively part of registration. For existing registrants it is a compliance obligation. Speak to IRAS or your tax adviser about your specific position.
Does this mean IRAS sees all my invoices?
IRAS receives invoice data for transactions in scope — broadly standard-rated and zero-rated supplies, and purchases where you claim input tax. Several categories are excluded, including point-of-sale supplies, simplified tax invoices and petty cash purchases. The stated purpose is faster GST processing through structured data rather than manual submissions.
Can I use my existing accounting software?
Only if it is InvoiceNow-ready or connects through an accredited access point. Ask your provider directly, and get a date if the answer is "not yet".
How long does onboarding take?
It depends on your solution provider. IRAS and IMDA both encourage starting well before your wave rather than close to it.
Sources
Information in this guide is sourced from IRAS (iras.gov.sg) and IMDA (imda.gov.sg). Verify current regulations before making compliance decisions. This guide is for general information only and does not constitute legal or financial advice.