Singapore InvoiceNow and GST InvoiceNow: What Every Business Must Know in 2026

Key Takeaways

• InvoiceNow is Singapore’s national Peppol-based e-invoicing network, run by IMDA — it lets businesses exchange structured digital invoices with any trading partner on the network.
• GST InvoiceNow is an additional IRAS requirement layered on top — it requires GST-registered businesses to also transmit a copy of that invoice data directly to the tax authority.
• Not every business is subject to GST InvoiceNow yet, but all new voluntary GST registrants from 1 April 2026 are in scope immediately, and all remaining GST-registered businesses must comply by 1 April 2031.
• A PDF invoice does not satisfy either requirement. InvoiceNow requires structured Peppol-format data; GST InvoiceNow requires that data to reach IRAS via an IMDA-accredited solution.
• SMEs can access free InvoiceNow-Ready Solutions until March 2031, plus up to $1,000 in transitional funding to offset onboarding costs.

What Is Singapore InvoiceNow?

InvoiceNow is Singapore’s nationwide e-invoicing network, introduced by the Infocomm Media Development Authority (IMDA) in 2019. It enables businesses to send and receive invoices as structured digital files — not PDFs, not emails — directly between accounting systems, using the internationally recognised Peppol standard.

The core benefit is automation. Unlike a PDF invoice that a recipient must manually key into their accounting system, an e-invoice sent via InvoiceNow delivers as structured data that integrates automatically. Invoice information is captured instantly, removing manual entry, reducing errors, and shortening payment cycles.

InvoiceNow is also Singapore’s standard for public sector procurement. Government agencies receive invoices via InvoiceNow as a default, which means any business supplying the public sector needs to be on the network.

As of 2026, over 63,000 businesses are already on the InvoiceNow network. The services available range from free e-invoicing portals to full accounting solutions and customised enterprise systems all offered by IMDA-accredited Access Point Providers (APs).

In short: InvoiceNow is about exchanging invoices more efficiently with your customers and suppliers. GST InvoiceNow adds a second destination to that same data flow — the tax authority.

What Is GST InvoiceNow and How Is It Different?

GST InvoiceNow is a mandatory requirement introduced by IRAS that requires GST-registered businesses to transmit prescribed invoice data directly to IRAS, in addition to exchanging invoices with their trading partners.

Where standard InvoiceNow is a two-party transaction — supplier sends invoice to buyer — GST InvoiceNow introduces a five-corner model. Singapore is the first country to implement this architecture: invoice data flows from the supplier’s accounting system, through their Access Point, via the InvoiceNow network, to the buyer’s Access Point and accounting system, with a copy simultaneously routed to IRAS.

This shifts Singapore’s GST compliance model from periodic reporting — where businesses submit GST returns quarterly or monthly — toward near real-time tax transparency, where IRAS receives invoice data as transactions occur.

	InvoiceNow	GST InvoiceNow
Run by	IMDA	IRAS (built on InvoiceNow infrastructure)
Purpose	Exchange structured invoices with trading partners	Transmit invoice data to IRAS for GST administration
Who must use it	Any business that wants to participate; mandatory for public sector suppliers	All GST-registered businesses (phased rollout 2025–2031)
What it replaces	Paper/PDF invoices	Does not replace GST return filing — both obligations continue
Technology	Peppol standard, IMDA-accredited Access Points	Same Peppol/PINT-SG infrastructure, IMDA-accredited InvoiceNow-Ready Solutions
Benefit	Faster payments, less manual entry, global interoperability	Faster GST audits, quicker refunds, reduced compliance risk

If your business is GST-registered, you are subject to GST InvoiceNow once your phase kicks in. If your business is not GST-registered, InvoiceNow remains available to you voluntarily — and is worth adopting for the operational efficiency gains alone.

The GST InvoiceNow Rollout: Which Phase Applies to You?

IRAS is implementing the GST InvoiceNow Requirement progressively, following the Committee of Supply Debate 2026 announcement that extended the mandate to all GST-registered businesses by April 2031.

Implementation Date	Who Is Affected
1 May 2025	Voluntary early adoption — open to all existing GST-registered businesses
1 November 2025	Newly incorporated companies that voluntarily register for GST
1 April 2026	All new voluntary GST registrants, regardless of incorporation date or structure
1 April 2028	New compulsory GST registrants; existing businesses with annual taxable turnover ≤ S$200,000
1 April 2029	Existing businesses with annual taxable turnover ≤ S$1,000,000
1 April 2030	Existing businesses with annual taxable turnover ≤ S$4,000,000
1 April 2031	All remaining GST-registered businesses

“Annual taxable turnover” means total standard-rated, zero-rated, and exempt supplies in all prescribed accounting periods ending in calendar year 2025.

Two groups are excluded:

1. Overseas entities, including those under the Overseas Vendor Registration regime.
2. Businesses registered solely under the Reverse Charge regime.

IRAS will notify existing GST-registered businesses of their specific mandatory implementation date by mid-2026. Do not wait for that letter. Use IRAS’s GST InvoiceNow Implementation Date Calculator (available on the IRAS website) to determine your date now.

What Transactions Must You Transmit to IRAS?

Under the GST InvoiceNow Requirement, businesses must transmit invoice data covering:

• Standard-rated supplies (excluding reverse-charge supplies)
• Zero-rated supplies
• Standard-rated purchases on which input tax claims are made or will be made (excluding reverse-charge purchases)

Invoice data is drawn from the documents you already issue and receive: tax invoices, simplified tax invoices, receipts with serial numbers, debit notes, and credit notes. There is no minimum transaction threshold — all qualifying transactions must be transmitted.

For high-volume, low-value transactions (retail point-of-sale, petty cash), IRAS permits businesses to aggregate multiple transactions into a single consolidated entry before transmitting.

Transmission deadline: Submit invoice data by the earlier of the date you file your GST return or the official filing due date for that return. If your GST period ends 31 March and the filing deadline is 30 April, all invoice data for that period must reach IRAS by 30 April — even if you file late.

How to Get InvoiceNow-Ready: Three Steps

Step 1: Adopt an IMDA-Accredited InvoiceNow-Ready Solution

InvoiceNow-Ready Solutions (IRSP list) are accounting or finance platforms accredited by IMDA, connected to an IMDA-approved Access Point. They transmit your invoice data via the Peppol network automatically. Check whether your current accounting software appears on IMDA’s IRSP list. Many widely used cloud accounting platforms are already accredited. If yours is not, switch or supplement it before your implementation date.

SMEs without an existing accounting solution can access free InvoiceNow-Ready Solutions until March 2031 under IMDA’s programme.

Step 2: Register in the SG Peppol Directory

Approach your chosen IRSP or AP to register your business in the SG Peppol Directory using your Unique Entity Number (UEN). You will receive a Peppol ID — the unique address that routes your invoice data correctly through the network to both your trading partners and IRAS.

Step 3: Enable the GST InvoiceNow Submission Feature

Once registered, activate the GST InvoiceNow transmission feature in your solution. From that point, a copy of your invoice data flows to IRAS automatically each time you issue or receive a qualifying invoice. Test the transmission with your IRSP before your mandatory date to confirm data is reaching IRAS correctly.

Common Mistakes Singapore Businesses Make

Treating InvoiceNow and GST InvoiceNow as the same thing. They share infrastructure but serve different purposes. Being on the InvoiceNow network for exchanging invoices with suppliers does not automatically mean you are transmitting data to IRAS. The GST InvoiceNow feature must be separately activated in your InvoiceNow-Ready Solution.

Sending PDFs and calling it done. A PDF invoice — even one delivered by email — does not satisfy either requirement. InvoiceNow requires structured Peppol-format data. GST InvoiceNow requires that structured data to also reach IRAS via an accredited solution.

Assuming existing accounting software qualifies. Many businesses use software that generates digital invoices but is not on IMDA’s accredited IRSP list. Check explicitly — “cloud accounting” does not automatically mean “InvoiceNow-ready.”

Waiting for IRAS’s notification letter. IRAS will notify existing GST-registered businesses by mid-2026 — but switching accounting software, registering in the SG Peppol Directory, and testing transmission typically takes several weeks. Starting after the letter arrives may leave you non-compliant at your deadline.

Missing available grants. The Government has introduced up to $1,000 in transitional funding for SMEs and up to $5,000 for larger businesses to offset InvoiceNow onboarding costs. SMEs are also eligible for the Productivity Solutions Grant to defray up to 50% of eligible software costs. These need to be claimed proactively.

Conclusion: How Grof Helps You Navigate Both Requirements

InvoiceNow and GST InvoiceNow together represent the most significant shift in Singapore’s invoicing and GST compliance infrastructure since the Goods and Services Tax was introduced. For SME founders and finance managers, the challenge is not just technical — it is understanding which requirement applies, when it kicks in, and whether your current accounting setup actually qualifies.

Grof’s accounting and corporate secretarial team helps Singapore-incorporated businesses work through both sides of this transition: assessing your current accounting software against the IMDA IRSP list, guiding Peppol registration, managing your GST filing obligations on an ongoing basis, and identifying the grants your business is eligible to claim.

Whether you are registering for GST for the first time, reviewing your accounting software ahead of a compliance deadline, or approaching the S$1 million turnover threshold that triggers compulsory registration, InvoiceNow readiness is now part of the compliance baseline.

FAQ: Singapore InvoiceNow and GST InvoiceNow