Singapore InvoiceNow E-Invoicing Requirements: 2025-2031 Guide

Singapore's InvoiceNow e-invoicing mandate requires every GST-registered business to transmit invoices through the Peppol network by April 2031. The phased rollout started in November 2025 with newly voluntarily registered GST businesses and will expand in stages from 2028 through 2031 based on annual revenue thresholds. Through its distinctive 5-corner Peppol model, IRAS receives real-time invoice data directly from the network, enabling automated GST compliance verification without manual filing or reconciliation.

This guide answers the critical questions facing Singapore finance teams right now:

The full 2025-2031 phased timeline with specific revenue bracket thresholds and compliance deadlines
How Singapore's 5-corner Peppol model works and why it differs from European e-invoicing frameworks
PINT-SG format and registration requirements for connecting to the InvoiceNow network
Penalties for non-compliance, including enforcement consequences and GST registration risk
Government grants and subsidies available to offset your adoption costs
Practical preparation steps to transition from paper or PDF invoicing to InvoiceNow-compliant transmission

The timeline is not distant. The April 2026 phase is months away, and approximately 90,000 additional businesses will need to join the InvoiceNow network before the final 2031 deadline. Businesses that delay risk compressed implementation windows, reduced access to grant funding, and potential penalties once their phase takes effect.

The first step toward meeting your Singapore e-invoicing requirements is understanding exactly what InvoiceNow is and whether your business falls within the current or upcoming compliance phases.

What Is InvoiceNow and Who Must Comply?

InvoiceNow is Singapore's nationwide e-invoicing framework built on the international Peppol network. It enables businesses to send and receive invoices electronically in a standardized digital format, transmitted directly between accounting systems without manual data entry, PDF exchanges, or paper documents.

The framework was jointly developed by the Inland Revenue Authority of Singapore (IRAS) and the Infocomm Media Development Authority (IMDA) as a core component of Singapore's digital economy strategy. Singapore holds a notable distinction here: it became the first non-European country to join as a Peppol Authority in 2018 and the first Asian country to adopt Peppol for e-invoicing. That early commitment laid the groundwork for what is now a mandatory national requirement.

Adoption has already reached significant scale. By April 2024, a joint IMDA-IRAS announcement confirmed over 60,000 businesses were already on the InvoiceNow network, well before the GST InvoiceNow mandate began taking effect in November 2025. Roughly 50% of government vendors are registered, and the network processes over 100 million e-invoices per year.

Who must comply? The InvoiceNow Singapore mandate covers all GST-registered businesses. This includes companies, limited liability partnerships (LLPs), sole proprietors, and partnerships holding GST registration. The GST InvoiceNow requirement applies regardless of industry or business size.

Only two narrow exemptions exist:

Businesses registered under the Reverse Charge regime
Overseas entities registered under the OVR Pay-only or OVR full regime

For everyone else with GST registration, compliance is not optional. Following the Committee of Supply 2026 announcement, approximately 90,000 additional businesses must join the InvoiceNow network by April 2031, extending the InvoiceNow mandatory Singapore requirement across the full GST-registered population.

Your specific compliance deadline depends on your business type and annual revenue tier.

Complete 2025-2031 Phased Rollout Timeline

Singapore's InvoiceNow mandate follows a deliberate phased approach announced during the Committee of Supply 2026 debates. The rollout logic is intentional: newly registered and smaller businesses come first because they can adopt off-the-shelf InvoiceNow-ready solutions with minimal IT effort, while larger enterprises with entrenched ERP systems get additional runway for integration planning.

Here is the complete InvoiceNow Singapore timeline across all seven phases:

Phase	Date	Who Must Comply
1	May 1, 2025	Soft launch period - voluntary early adoption for all GST-registered businesses
2	November 1, 2025	Mandatory for newly incorporated companies with voluntary GST registration
3	April 1, 2026	Mandatory for all new voluntary GST registrants, including companies, LLPs, sole proprietors, and partnerships
4	April 1, 2028	New compulsory GST registrants + existing businesses with total annual supplies under ~SGD 200K
5	April 1, 2029	Existing GST-registered businesses with total annual supplies under ~SGD 1M
6	April 1, 2030	Existing GST-registered businesses with total annual supplies under ~SGD 4M
7	April 1, 2031	All remaining GST-registered businesses, regardless of revenue

The revenue bracket thresholds for the 2028-2031 Singapore e-invoicing mandate phases are approximate, based on currently available regulatory guidance. IRAS has confirmed it will notify pre-2026 GST-registered businesses of their specific compliance date by mid-2026, so businesses operating before the Singapore e-invoicing mandate 2026 cutoff should watch for direct IRAS correspondence.

The phased structure means most existing businesses have until at least April 2028 before compliance becomes mandatory, but the voluntary soft launch from May 2025 provides a low-risk window to test your setup before deadlines apply.

How Singapore's 5-Corner Peppol Model Works

Most countries that adopt Peppol-based e-invoicing use a 4-corner model. The flow is straightforward: the supplier's accounting system sends an invoice to the supplier's Access Point (Corner 1 to Corner 2), which routes the document through the Peppol network to the buyer's Access Point (Corner 3), which delivers it to the buyer's system (Corner 4). The tax authority is not directly involved in the transmission. If you want to understand how e-invoicing works globally across different mandate structures, that broader context is helpful before examining what makes Singapore's approach distinctive.

Singapore adds a 5th corner: IRAS itself. When an invoice passes through the Peppol network between the supplier's and buyer's Access Points, IRAS receives a copy of the invoice data via API in real time. IRAS does not intervene in or approve the transaction. It functions as a passive receiver, collecting a mirror of every B2B invoice exchanged through the InvoiceNow infrastructure.

This 5th corner enables what is known as Continuous Transaction Controls (CTC). Under a traditional GST compliance model, businesses compile their own transaction records, calculate GST liability, and file periodic returns. IRAS then audits those self-reported figures after the fact. With CTC, that sequence inverts. IRAS receives the underlying transactional data as invoices are exchanged, building its own real-time picture of each business's GST position. GST reporting shifts from being a separate compliance exercise to becoming a byproduct of normal B2B invoice exchange.

The contrast with European approaches is significant. Most EU e-invoicing mandates, including those in France, Germany, Italy, and Spain, use variations of the 4-corner model or centralized clearance platforms where invoices must be validated before reaching the buyer. Singapore's CTC approach through the InvoiceNow 5-corner model is technically distinct. Rather than inserting a validation or clearance step into the invoice flow, it layers tax authority visibility on top of the existing Peppol transmission without adding friction to the supplier-buyer exchange.

The practical implication for your business is direct: every data point in your e-invoices will be visible to IRAS. Line items, GST calculations, supplier and buyer identifiers, and transaction values all flow to the tax authority as part of the standard transmission process. Errors or inconsistencies in your invoice data will not sit unnoticed in a filing cabinet until a periodic audit. They will be flagged by IRAS as the data arrives. This makes accuracy in invoice content and GST treatment a front-line compliance concern rather than something caught months later.

To transmit compliant invoices through this 5-corner model, your business must meet specific format standards and complete a registration process with an approved Access Point.

PINT-SG Format and Registration Requirements

Meeting InvoiceNow obligations requires more than registering on a portal. Your business must generate e-invoices in the correct technical format, connect to the Peppol network through an approved provider, and maintain compliant records for years afterward. This section covers each requirement so your finance and IT teams know exactly what to implement.

The PINT-SG Invoice Standard

PINT-SG (Peppol International - Singapore) is the mandatory format for all InvoiceNow e-invoices. Built on OASIS UBL 2.1 XML, PINT-SG replaced the earlier SG Peppol BIS Billing 3.0 standard, which was phased out on May 30, 2025. Any e-invoice transmitted through the Peppol network after that date must conform to the PINT-SG specification.

The standard covers a broad range of document types:

Invoices and credit notes
Purchase orders and invoice responses
Aggregated cash sales and petty cash purchases
Serialised receipts and debit notes

Every PINT-SG document must include specific mandatory data elements:

Supplier and buyer details, including company names and addresses
UENs (Unique Entity Numbers) for both transacting parties
GST registration numbers where applicable
Tax invoice amounts and line items with itemised descriptions
GST treatment classification for each line item: standard-rated, zero-rated, or exempt
GST calculations showing the tax amount derived from each applicable rate

For the underlying GST tax invoice formatting rules that InvoiceNow digitises into structured data, businesses should be familiar with Singapore GST tax invoice formatting rules to ensure their source documents are correct before transmission.

Registration and Peppol ID

To transmit e-invoices on the Peppol network, your business needs a Peppol ID. Registration requires authenticating through CorpPass, the government's corporate digital identity platform that handles KYC certification. Your Peppol ID is tied to your company's UEN, which serves as the unique network identifier for receiving and sending documents.

Connecting to the Peppol Network

Once registered, you must connect through one of two approved channel types:

IMDA-accredited Access Point providers - These are network service providers certified by the Infocomm Media Development Authority to transmit documents on the Peppol network.
InvoiceNow-Ready Solution Providers (IRSPs) - These are software vendors whose accounting or ERP solutions have built-in InvoiceNow connectivity, allowing you to send and receive e-invoices directly from your existing business system.

Your choice depends on your current technology stack. Businesses already using an IRSP-certified accounting package may need minimal additional setup, while those on legacy systems will likely route through a standalone Access Point provider.

Transmission Deadlines

E-invoices must be transmitted to IRAS by the earlier of two dates: the actual date you file your GST return, or the official GST return due date for that period. Missing this window means the invoice data was not reported within the compliance timeframe, regardless of whether the invoice itself was issued on time.

Validation and Compliance Checks

Before transmission, you can verify your e-invoices against the PINT-SG specification using Validex, a format compliance checking tool. This catches structural errors, missing fields, and formatting issues before they reach IRAS.

On the receiving end, IRAS performs its own validation layer. The tax authority checks that the supplier's GST registration status is valid, scans for duplicate invoice submissions, and flags potentially wrongful GST charges. These automated checks mean formatting errors or data inconsistencies will be identified quickly.

Archiving Obligations

All e-invoices must be archived for a minimum of 5 years in their original format. You cannot convert a PINT-SG XML document into a PDF and discard the XML - the original structured file must be retained. Storage abroad is permitted under Singapore's rules, provided the records remain accessible to IRAS upon request within a reasonable timeframe.

While InvoiceNow enforcement takes a calibrated approach during the initial rollout phases, there are clear consequences for businesses that fail to meet these requirements once their compliance window opens.

Penalties for Non-Compliance with InvoiceNow

Most publicly available guides on Singapore's InvoiceNow mandate skip over penalties entirely, leaving businesses with no clear picture of what happens if they miss their compliance deadline. This is a significant gap, because IRAS does hold meaningful enforcement powers under the GST framework.

The primary consequence is structural rather than a simple fine. IRAS may refuse to approve new GST registration or revoke existing GST registration for businesses that fail to comply with the InvoiceNow requirement. GST registration revocation carries cascading effects: your business loses the ability to claim input tax credits on purchases, which directly increases operating costs. It also creates complications for your GST-registered suppliers and customers, who may need to adjust their own tax reporting and pricing arrangements. For businesses embedded in B2B supply chains, this disruption extends well beyond a single compliance failure.

That said, IRAS has signaled a calibrated enforcement approach during the initial rollout phases. Genuine mistakes, technical difficulties during onboarding, and good-faith efforts to comply will not trigger harsh penalties. The stated priority is driving adoption across the ecosystem, not punishing businesses that encounter early difficulties with the transition. If your organization is among the first waves of mandatory adopters, IRAS is giving you room to work through implementation challenges without immediate repercussions.

Businesses that identify errors in their InvoiceNow submissions after the fact can use the Voluntary Disclosure Programme to proactively report those errors to IRAS. Self-reported disclosures through this programme typically receive more favorable treatment than errors uncovered during an IRAS audit. If your team spots a formatting issue, incorrect data field, or submission gap, reporting it voluntarily is the lower-risk path.

One critical point for businesses in the later compliance phases (2028-2031): do not assume the same calibrated leniency will apply by the time your mandate date arrives. As the InvoiceNow ecosystem matures and early-phase businesses establish operational norms, IRAS enforcement expectations will tighten. Businesses with compliance deadlines in 2029 or later will be entering a more established regulatory environment where the tolerance for implementation struggles is considerably narrower.

While the regulatory framework sets clear expectations and consequences, the Singapore government is also backing InvoiceNow adoption with substantial financial support to help businesses make the transition.

Government Grants and Subsidies for InvoiceNow Adoption

Singapore's government has committed substantial funding to reduce the financial burden of InvoiceNow adoption, with multiple overlapping programmes targeting businesses of different sizes and stages. Understanding what is available, and when each programme expires, lets you capture the maximum benefit before deadlines pass.

S$1,000 SME Grant. GST-registered SMEs can receive a one-time S$1,000 grant to offset the operational costs of adopting InvoiceNow. This covers expenses such as software subscriptions, staff training, and process adjustments during the transition period.

S$5,000 Early Adopter Grant. Larger organisations that voluntarily adopt InvoiceNow ahead of their mandatory compliance deadline can claim up to S$5,000. This reward for proactive adoption recognises the effort involved in early implementation and encourages businesses to move before the regulatory wave reaches them.

Productivity Solutions Grant (PSG). The PSG provides up to S$30,000 per business, covering 50% of eligible costs for pre-approved IT solutions and consultancy services related to e-invoicing. The grant has been extended through March 2026, giving businesses a defined window to invest in InvoiceNow-ready accounting and ERP systems at half the sticker price.

Free-of-Charge Solution Packages. Select IMDA-accredited providers offer free InvoiceNow solution packages to qualifying businesses. These packages are available through March 2031, aligning with the final phase of the mandatory rollout timeline. For SMEs with basic invoicing needs, these free packages may cover the entire technical requirement at zero cost.

InvoiceNow Accelerate Programme. Newly incorporated businesses receive 1 year of free InvoiceNow service through this programme, removing the adoption cost barrier entirely for startups and new entities entering the market.

Enterprise Clinic. Free consultation sessions are available for businesses that need guidance on their InvoiceNow implementation approach. Each company can send a maximum of 3 participants to these clinics, which cover technical setup, process design, and compliance planning.

When stacked together, these programmes can substantially offset or even eliminate adoption costs. An SME could combine the S$1,000 grant with a free solution package and an Enterprise Clinic session to achieve compliance with minimal out-of-pocket expense. Businesses with more involved requirements can layer the PSG's S$30,000 ceiling on top of the other grants to fund ERP integrations and professional consultancy. With over 200 IMDA-accredited service providers in the ecosystem, competition among vendors further drives down costs beyond what the grants themselves cover.

The critical detail is timing. The PSG extension runs only through March 2026, and while free solution packages extend to March 2031, grant programmes can be modified or exhausted before their stated end dates. Businesses that apply while funding is fully available secure the best financial outcome.

Preparing Your Business for InvoiceNow Compliance

Preparation requirements differ significantly based on your business size and current level of digitization. A sole proprietor running invoices through accounting software faces a fundamentally different adoption path than an enterprise with a legacy ERP system, and both differ from a business still processing paper invoices manually. The guidance below is organized accordingly.

SMEs and Smaller Businesses: Adopt InvoiceNow-Ready Software

For most small and medium enterprises, the fastest path to Singapore InvoiceNow compliance is adopting an accounting software solution that already supports InvoiceNow and Peppol. Several platforms are accredited and actively used in Singapore:

Xero - cloud-based, popular among small businesses and bookkeepers
ABSS Accounting (formerly MYOB) - widely used across Southeast Asia
AutoCount - strong adoption among Singapore SMEs
Microsoft Dynamics 365 Business Central - suits mid-market companies scaling up
Sage 300 - established in multi-entity and project-based businesses
Million Accounting Software - built for the Singapore and Malaysian markets

These InvoiceNow-ready solutions handle Peppol format conversion, UEN-based routing, and transmission through accredited Access Points automatically once configured. You select your Access Point provider during setup, connect your Peppol ID, and the software manages the technical requirements behind the scenes.

Larger Businesses: Plan for System Integration

Enterprises with existing ERP or accounting systems need a different approach. Rather than replacing core financial software, these businesses integrate with an IMDA-accredited Access Point provider or Invoice Reporting Service Provider (IRSP) through APIs or middleware connectors.

This integration involves several workstreams: IT project planning to map data flows between your ERP and the Peppol network, system testing to validate that invoices conform to PINT-SG schema requirements, and staff training to ensure accounts receivable and accounts payable teams understand the new workflows. Budget 3 to 6 months of implementation lead time from vendor selection through go-live, factoring in procurement cycles, UAT testing against the PINT-SG schema, and validation of GST treatment classifications across your invoice portfolio.

Solving the Paper-to-Digital Transition Challenge

A preparation gap that most compliance guides overlook: many Singapore businesses still process invoices on paper or as unstructured PDF files. Before you can connect to InvoiceNow, your invoice data needs to exist in structured digital form. This creates two distinct challenges.

First, establishing digital-first processes going forward. Every invoice your business issues or receives after your compliance deadline must flow through InvoiceNow-ready software. If your current workflow involves printing invoices, mailing paper copies, or emailing unformatted PDFs, those processes need to be rebuilt around your chosen digital platform.

Second, digitizing historical invoice data for migration. When you transition to new accounting software or connect your ERP to an Access Point, you may need to import historical invoice records. Supplier master data, recurring invoice templates, pricing structures, and outstanding receivables all need to move from paper or PDF into your new system.

For businesses managing this transition, tools designed for digitizing paper invoices through scanning and data capture can accelerate the process considerably. Financial document processing platforms accept batches of PDF and scanned invoices, apply natural language extraction instructions (for example, "extract invoice number, date, vendor name, and total for GST compliance"), and output structured Excel, CSV, or JSON files ready for import into accounting software. Some platforms handle up to 6,000 documents in a single batch, making it practical to automate invoice data extraction for InvoiceNow compliance rather than re-keying years of paper records by hand.

Your Preparation Checklist

Work through these steps in order, starting as early as possible before your compliance deadline:

Determine your compliance phase and deadline. Check whether your business falls into the May 2025 voluntary, November 2025 newly registered, or later mandatory phase based on revenue thresholds.
Audit your current invoice workflow. Document how invoices are created, sent, received, and recorded today. Identify where paper, email, and manual data entry are involved.
Choose an InvoiceNow-ready solution or Access Point provider. SMEs should evaluate accredited accounting software. Larger businesses should assess IMDA-accredited Access Points compatible with their ERP.
Apply for relevant grants. Submit your Productivity Solutions Grant (PSG) or SMEs Go Digital application before purchasing software, as grants require pre-approval.
Register for a Peppol ID via CorpPass. Log in to the Peppol Directory through CorpPass and register your business's UEN as your Peppol participant identifier.
Digitize existing paper and PDF invoice data if needed. Convert unstructured invoice records into structured digital formats for import into your new system.
Run a pilot with test invoices using the Validex tool. Validate that your outgoing invoices conform to the PINT-SG format before sending live transactions.
Train staff on the new workflow. Ensure both AR and AP teams understand how to issue, receive, and reconcile invoices through the InvoiceNow network.

Do Not Overlook the Accounts Payable Side

Compliance is not only about issuing invoices. Your business also needs to prepare to receive and process incoming e-invoices through the Peppol network. This means configuring your accounting system to accept inbound PINT-SG documents, mapping incoming invoice data fields to your chart of accounts, and updating AP matching and approval workflows to work with structured e-invoice data rather than PDF attachments.

During the transition period, your AP team will operate in mixed mode: some suppliers will send invoices through InvoiceNow while others continue using PDF, email, or paper. Plan for parallel processing during this window. Your accounting system needs to handle both InvoiceNow-received and manually-entered invoices within the same approval workflow. As more of your suppliers come online with InvoiceNow through 2027 and beyond, the balance will shift progressively toward fully digital receipt.

One advantage of receiving e-invoices through the Peppol network is that the structured PINT-SG data eliminates the need for manual data entry on the AP side. Invoice matching, GST input credit verification, and payment scheduling can all be automated once your system is configured to ingest PINT-SG data directly.

Your InvoiceNow Compliance Action Plan

Singapore's InvoiceNow mandate covers every GST-registered business in the country, with compliance deadlines staggered from April 2026 for new voluntary GST registrants through April 2031 for all remaining businesses. Your next steps depend on which phase applies to you.

If your deadline is April 2026: Act now. Register for a Peppol ID through CorpPass, select an InvoiceNow-ready accounting solution that supports the PINT-SG format, and submit your grant applications while funding is available. Begin test submissions through the Validex sandbox environment to identify formatting issues before your compliance date arrives. With months rather than years on the clock, parallel execution of these steps is essential.

If your deadline falls in 2028-2029 (smaller existing GST-registered businesses): Start evaluating solutions today, even though your mandatory date is further out. The Productivity Solutions Grant (PSG) and other IMDA-backed subsidies can offset a significant portion of your implementation costs, but grant budgets are finite and conditions change. Use this lead time to digitize any remaining paper-based invoice processes, train staff on e-invoicing workflows, and run pilot transactions with key trading partners.

If your deadline falls in 2030-2031 (larger existing GST-registered businesses): The longer runway is an advantage only if you use it for thorough preparation rather than delayed action. Begin planning your IT system integration now. Evaluate Access Point providers based on your transaction volume and ERP compatibility. Budget for implementation across multiple fiscal years. Large organizations with complex supplier networks benefit most from phased internal rollouts that surface integration issues early.

Singapore's InvoiceNow mandate is part of a broader global shift toward mandatory e-invoicing. Malaysia began mandating Peppol-based e-invoicing in 2025, Japan joined as a Peppol Authority in 2021, and Korea and India are running national Peppol pilots. Countries beyond Asia are following the same trajectory, including South Africa's upcoming e-invoicing mandate. For Singapore businesses with regional trade relationships, cross-border Peppol invoicing is already operational, meaning your InvoiceNow investment extends beyond domestic compliance to cover ASEAN and international supply chains.

Compliance with the InvoiceNow Singapore mandate is both a regulatory requirement and an operational upgrade. Standardized e-invoicing eliminates manual data entry errors, real-time GST reporting through IRAS's 5-corner model reduces audit risk, and government grant support lowers the financial barrier to adoption. Whether your deadline is 2026 or 2031, the case for early action is the same: better preparation, lower risk, and faster return on your investment.