From 1 April 2026, all newly GST-registered companies in Singapore must transmit invoice data to IRAS via the InvoiceNow network. By 2031, this becomes mandatory for every GST-registered business in Singapore. If you incorporate now and plan to register for GST - voluntarily or once you cross S$1M turnover - this affects you. Here's what to do, when to do it, and what it costs.

InvoiceNow is Singapore's nationwide e-invoicing network, built on the Peppol standard. It lets businesses send invoices directly between accounting systems - no PDFs, no emails, no manual data entry. From April 2026 onwards, IRAS uses this network to receive invoice data in real time as part of GST filing.

What is InvoiceNow, exactly?

InvoiceNow is the Singapore brand for the international Peppol e-invoicing network. Peppol is a global standard that lets a sending system in Singapore deliver a structured invoice directly to a receiving system anywhere on the network - including buyers in Australia, the EU, Japan, Malaysia, and other Peppol-enabled jurisdictions.

Think of it like email for invoices: instead of attaching a PDF and hoping the recipient types the numbers correctly into their system, the data flows in machine-readable form from your accounting software to theirs.

Why Singapore is mandating it for GST: IRAS gets near-real-time visibility into invoice flows. Instead of relying on companies to summarise transactions quarterly in their GST F5 return, IRAS receives the data as it happens. This reduces fraud, automates GST refund verification, and lets the agency move toward continuous compliance rather than annual audit cycles.

The phased timeline (2026 to 2031)

IRAS is rolling out the InvoiceNow GST requirement in three phases. Mark your calendar based on when you incorporate and when you register for GST.

Phase 1 - 1 May 2025 (already live)

Voluntary early adoption open to all GST-registered companies. Businesses that adopt early get IRAS support and certain compliance reliefs.

Phase 2 - 1 November 2025

Mandatory for all newly incorporated companies that voluntarily register for GST. If you incorporated after this date and choose voluntary GST registration, you must use InvoiceNow.

Phase 3 - 1 April 2026 (the big one)

Mandatory for all newly GST-registered businesses, whether registration is voluntary or compulsory (after crossing S$1M turnover).

Phase 4 - 2028 onwards

IRAS has signalled progressive expansion to existing GST-registered businesses, with full mandate by 2031. Exact dates per cohort will be confirmed closer to time.

Who is affected right now?

If you fall into any of these categories, InvoiceNow GST applies to you:

If you have an existing Singapore Pte Ltd that is already GST-registered, you have time. But if you incorporate today and plan to register for GST, you should plan for InvoiceNow from day one rather than retrofit later.

What you actually need to do

There are four practical steps to comply:

  1. Choose an InvoiceNow-ready accounting system or solution provider. Xero, Quickbooks Online, SAP Business One, Microsoft Dynamics, and most modern Singapore-friendly accounting systems are either already enabled or have InvoiceNow modules. Karman's accounting clients are migrated automatically.
  2. Get a Peppol ID (also called a Peppol Participant Identifier). Your accounting software or service provider issues this. It's how invoices route to your business on the Peppol network.
  3. Register your Peppol ID with IMDA's registry (the Infocomm Media Development Authority runs the Singapore Peppol Authority). This makes your business discoverable on the network.
  4. Configure transmission to IRAS for GST data. Your accounting system or solution provider handles this; it's a configuration setting, not a separate filing.

Once configured, your sales and purchase invoices flow into IRAS automatically. You still file your GST F5 return as normal, but the underlying transaction data is already with IRAS by the time you file - which means refund verification is much faster.

Cost and time commitment

Time to implement: 2-4 weeks for most small businesses. Most of this is configuration with your accounting system provider. Direct cost: If you're already on a modern cloud accounting system (Xero, QBO), the InvoiceNow capability is typically included or available as a low-cost add-on (S$0-S$30/month). Some access-point providers charge per-invoice for high volumes. Ongoing cost: Negligible if your invoice volume is under 1,000/month. Higher volume businesses may negotiate volume pricing with their access-point provider. If you don't have accounting software yet: This is the moment to set one up. Trying to InvoiceNow-comply without a proper accounting system is far more painful than picking the right system from day one.

What changes operationally

Day-to-day, very little visible change for most founders. You still issue invoices the way you always have - through your accounting system. The difference is that the system silently transmits invoice data to IRAS in the background and to your customers (if they're also on Peppol) directly into their system.

What you'll notice: What you don't have to do: You don't need to send invoices via Peppol to consumers (B2C). Retail receipts and consumer-facing invoices are out of scope for now. The mandate is for B2B and IRAS reporting.

Should you adopt early (before April 2026)?

If you're newly incorporated and plan to register for GST, the answer is straightforward: yes, set up InvoiceNow at the same time you set up your accounting system. The marginal effort is tiny when you're starting fresh.

If you're an existing GST-registered business not yet required to comply: voluntary adoption gives you a smoother transition window, IRAS implementation support, and time to fix any data quality issues before it becomes mandatory in 2028+. Most Karman accounting clients in this category are migrating in 2026 rather than waiting for the mandate.

How Karman handles this for clients

If you incorporate with Karman and use our accounting service, InvoiceNow setup is included. We pick the right accounting system (Xero is our default), configure your Peppol ID, register with IMDA, and connect transmission to IRAS - usually before your first GST filing is due.

If you've already incorporated and want help migrating, our accounting team can audit your current setup and migrate you onto an InvoiceNow-ready stack. The earlier you do this, the smoother subsequent GST filing cycles will be.

Official Sources

Frequently Asked Questions

No - InvoiceNow GST reporting only applies to GST-registered businesses. However, you can still use the Peppol network to send invoices to customers who are on it. Many Karman clients adopt InvoiceNow before GST registration to streamline B2B invoicing.

Failure to comply with the InvoiceNow GST requirement is treated as a GST registration condition breach. IRAS can refuse to process your GST registration or, for already-registered companies covered by future mandates, impose penalties consistent with other GST non-compliance (S$200-S$1,000 administrative penalties, plus continued non-compliance can attract compounded penalties).

No. You still file the GST F5 return quarterly (or monthly, depending on your filing frequency). InvoiceNow transmits the underlying transaction data to IRAS, which makes the F5 reconciliation simpler and refund verification faster, but the F5 return is still submitted via the myTax Portal.

Yes. Both Xero and Quickbooks Online support InvoiceNow / Peppol e-invoicing in Singapore. Xero has native support; Quickbooks works through certified access-point providers. Karman uses Xero by default for accounting clients - InvoiceNow is configured during onboarding.

No. The Peppol network is international. You can send invoices to customers in Australia, New Zealand, EU member states, Japan, Malaysia, and any other Peppol-enabled jurisdiction. Domestic Singapore invoices flow into IRAS for GST reporting; international invoices flow to the recipient but don't typically trigger GST reporting (since exports are zero-rated).