InvoiceNow accounting software in Singapore moved from nice-to-have to legal requirement once IRAS tied GST reporting to it. From 1 April 2026, every new voluntary GST registrant must transmit invoice data through the network, and the mandate reaches all GST-registered businesses by April 2031. This blog walks you through finding your deadline and getting ready, using a Singapore-ready cloud accounting system.

What is InvoiceNow, and what does the GST InvoiceNow requirement mean?

InvoiceNow is Singapore’s nationwide e-invoicing network, run by IMDA since 2019 on the Peppol standard. The GST InvoiceNow requirement is the IRAS rule that makes in-scope GST-registered businesses transmit structured invoice data straight to the tax authority through that network, replacing PDF and paper for statutory reporting.

The mechanism is direct transmission, not a separate filing. Your accounting system sends a structured invoice over the Peppol network, and IRAS receives a copy through a fifth corner added to the model in 2025. That copy feeds GST administration, which is why IRAS expects faster refunds and quicker audits from businesses on the network. By February 2026, more than 63,000 businesses were already transmitting through InvoiceNow, and the Committee of Supply 2026 schedule will pull in roughly 90,000 more.

When is your IRAS InvoiceNow deadline?

Your deadline depends on how and when you registered for GST. The phased schedule started on 1 November 2025 for newly incorporated companies that register for GST voluntarily within six months of incorporation, then extended to all new voluntary GST registrants on 1 April 2026 regardless of incorporation date.

Existing businesses come in by size, measured on total annual supplies across accounting periods ending in calendar year 2025. The 1 April 2028 wave covers new compulsory registrants and existing businesses with total annual supplies of S$200,000 or less. The 1 April 2029 wave takes in those up to S$1 million, 1 April 2030 reaches those up to S$4 million, and 1 April 2031 captures everyone above S$4 million. IRAS sequenced the smallest businesses first so government support could concentrate there. You do not need to wait for the letter; IRAS notifies pre-2026 registrants of their date by mid-2026, but the IRAS Implementation Date Calculator already lets you self-assess now.

Who has to comply with GST InvoiceNow, and who is exempt?

Every GST-registered business in Singapore is in scope by April 2031, with the date set by registration type and revenue. Scope is decided by GST status and the phase-in schedule, not by industry.

A few groups sit outside it. Overseas entities registered under the Overseas Vendor Registration regime are exempt, and so are businesses registered solely under the Reverse Charge regime, since those entities are not making taxable outward supplies. Parts of the financial services sector carry exclusions too, though IRAS has signalled the boundaries can shift. For a standard GST-registered company in professional services, retail, or distribution, there is no exemption to plan around. The realistic question is not whether you comply, it is which of the 2028 to 2031 waves you land in.

What format do you need: PINT-SG, Peppol, and the Access Point?

You need invoices in the PINT-SG format, sent through a Peppol Access Point. PINT-SG is the Peppol International billing specification for Singapore, and it replaced the older SG Peppol BIS Billing 3.0 profile that most older guides still reference.

This is the technical detail that catches teams out. A solution that only produces SG BIS Billing 3.0 is working to a superseded spec; the current Singapore standard is PINT-SG, which IMDA adopted as the Peppol Authority for the country. Transmission runs through a certified Peppol Access Point, the provider that connects your system to the network and routes the invoice. IRAS connected itself to that network as Corner 5, the recipient that captures invoice data for tax. EY Singapore is blunt about the framing: it calls this “a data and technology implementation, not just a tax project.” The format and the Access Point are where that technical reality starts.

How do you get InvoiceNow-ready before the deadline?

Start with three moves: pick an InvoiceNow-ready solution, connect through an Access Point, and clean your master data. The order matters, because the data work takes longest and teams underestimate it.

Choose a solution from the IRAS list of InvoiceNow-Ready Solutions so the PINT-SG output and Access Point connection are already certified rather than something you build. Map your customer, vendor, tax code, and unit-of-measure data to the Peppol code lists next, since mismatches there cause the validation rejections that stall go-live. Run a soft-launch period where you transmit voluntarily before your mandatory date, which IRAS opened from 1 May 2025 precisely so businesses could test against real submissions. Teams running this on cloud accounting tend to move faster, because managed cloud setup removes the server and patching work that on-premise systems add to an already tight timeline. Worth noting: onboard at least a quarter before your deadline, not the week of.

Is there government funding for InvoiceNow onboarding?

Yes. The government introduced transitional funding to offset onboarding costs, set at up to S$1,000 for SMEs and up to S$5,000 for larger businesses. SMEs can also use InvoiceNow-Ready Solutions free of charge until March 2031.

That funding is separate from the broader technology grants and is aimed squarely at the cost of getting onto the network. It pairs with the Enterprise Development Grant for the larger system project a finance team often runs alongside InvoiceNow readiness, where EDG covers up to 50% of qualifying costs for SMEs through a consultant-led proposal. The practical read is that the onboarding itself is cheap to subsidise, while the accounting system behind it is the real investment. Budget the grant for the connection, and scope the system separately.

What happens if you miss your IRAS deadline?

Missing the date puts your GST compliance at risk, not just your admin. For new voluntary registrants from 1 April 2026, using an InvoiceNow-ready solution is a condition of registration, so the registration itself can be rejected without it.

For existing businesses, the exposure is data quality rather than a single penalty event. Once you transmit, IRAS holds a copy of your invoice data, and discrepancies between that data and your filed GST return trigger reconciliation work. Inaccurate or duplicate transmissions create exactly those gaps. A finance team that switches on transmission without clean data trades a deadline problem for a reconciliation problem that recurs every filing period. The fix is to get the data right before the mandatory date, not after, which is the entire case for onboarding during the voluntary window.

Does your accounting software need to change for InvoiceNow?

Often, yes. If your current system cannot emit a PINT-SG invoice and connect to a Peppol Access Point, it needs replacing or extending, and bolt-on workarounds tend to break at the validation step.

This is where the system choice and the compliance deadline become one decision. Sage Intacct handles Singapore InvoiceNow through the Greytrix Singapore Localization Suite, built by Greytrix as a Sage Development Partner, which maps the platform to PINT-SG and handles GST F5 to F8 reporting. For groups on older Sage 300 systems, the same question applies: confirm the InvoiceNow path before the wave that catches you, because a multi-entity group has more invoice flows to validate than a single company. The cleaner approach is to treat InvoiceNow readiness as a property of your finance system, picked deliberately, rather than a feature you try to graft on at the last minute.

InvoiceNow readiness in Singapore is a sequencing problem with a fixed clock. Find your wave from your CY2025 total annual supplies, confirm your system can transmit PINT-SG through an Access Point, and clean your master data before you switch transmission on. The businesses that struggle are the ones that wait for the IRAS letter instead of self-assessing now.

Pull your total annual supplies figure, then book a session to map your IRAS deadline against your current system and a Sage Intacct readiness plan with a certified consultant.

FAQs About Invoicenow Accounting Software Singapore

What data does InvoiceNow send to IRAS? 

InvoiceNow transmits structured invoice data for standard-rated supplies at 9% GST, zero-rated supplies such as exports, exempt supplies, and standard-rated purchases where input tax is claimed. The data goes directly to IRAS over the Peppol network through Corner 5, replacing PDF invoices for statutory GST reporting.

What is a Peppol Access Point? 

A Peppol Access Point is the certified provider that connects your accounting system to Singapore’s InvoiceNow network and routes invoices in PINT-SG format. IMDA, as Singapore’s Peppol Authority since 2019, accredits these providers, and every business transmitting to IRAS sends through one.

Is InvoiceNow the same as e-invoicing? 

InvoiceNow is Singapore’s specific e-invoicing network, run by IMDA on the open Peppol standard. E-invoicing is the general practice; InvoiceNow is the national implementation that connects businesses and, since 2025, IRAS. By April 2031 all GST-registered businesses must use it for invoice data.

How do I find my GST InvoiceNow implementation date? 

Use the IRAS Implementation Date Calculator and your total annual supplies across accounting periods ending in calendar year 2025. Existing businesses fall into waves from 1 April 2028 to 1 April 2031 by revenue. IRAS will also notify pre-2026 registrants of their date by mid-2026.