Singapore’s InvoiceNow: Everything You Need to Know About e-Invoicing in Singapore

Singapore’s digital transformation agenda has reached a critical milestone with the phased implementation of InvoiceNow, the nationwide e-invoicing framework administered by the Infocomm Media Development Authority (IMDA) and the Inland Revenue Authority of Singapore (IRAS). 

This blog will provide an in-depth examination of InvoiceNow’s architecture, compliance requirements, benefits, and alignment with the GST InvoiceNow Requirement mandate announced in 2025.

What is InvoiceNow Singapore?

InvoiceNow, Singapore's nationwide e-invoicing initiative, was first introduced in 2019 by the Infocomm Media Development Authority (IMDA). Initially, InvoiceNow was a voluntary e-invoicing framework designed primarily for business-to-business (B2B) and business-to-government (B2G) transactions. It aimed to facilitate the digital exchange of invoices in a structured electronic data format directly between different accounting and finance systems, thus eliminating manual data entry and reducing errors.

The framework is built upon the international Peppol (Pan-European Public Procurement Online) standard, making Singapore the first country outside Europe to adopt Peppol at a governmental level. Peppol provides standardized specifications for secure and interoperable electronic document exchanges, especially invoices.

Evolution to GST InvoiceNow Mandate

In April 2024, the Inland Revenue Authority of Singapore (IRAS), in collaboration with IMDA, announced a phased implementation of the GST InvoiceNow Requirement. This new mandate extends InvoiceNow's scope from voluntary use to compulsory adoption for specific categories of GST-registered businesses starting from May 2025.

To make sure there is no confusion: here is the exact difference between InvoiceNow and GST InvoiceNow Mandate

1. InvoiceNow: A general-purpose e-invoicing framework that has been available since 2019, allowing businesses to exchange structured invoices electronically without manual intervention.
2. GST InvoiceNow Mandate: A specific regulatory requirement announced in 2024 that mandates the use of InvoiceNow for transmitting invoice data to IRAS, ensuring compliance with GST laws.

InvoiceNow Solutions

InvoiceNow solutions refer to IMDA-accredited software products that enable businesses to send and receive electronic invoices via the Peppol network. These solutions are categorized as:

• InvoiceNow-Ready Solutions: Off-the-shelf accounting software (e.g., Xero, QuickBooks, SAP Business One) pre-integrated with the InvoiceNow network.
• Customized ERP Integrations: Tailored solutions for larger enterprises using ERP systems like SAP or Oracle.

Businesses can select from over 80 accredited solutions listed on IMDA's official portal. SMEs without existing accounting software can adopt free or subsidized solutions provided under IMDA's InvoiceNow Accelerate Program.

InvoiceNow Portal

IMDA maintains an official InvoiceNow portal which simplifies onboarding by guiding businesses through each step from selecting suitable software, activating their unique Peppol to providing comprehensive resources such as:

• Accredited solution provider lists
• Technical documentation and guidelines
• Registration processes
• Training materials and support resources

The InvoiceNow Network Architecture

4-Corner Model (Original Implementation): 

Initially, InvoiceNow operated on a "4-corner model,". This model facilitated direct invoice transmission between trading partners without involving tax authorities.

Supplier's accounting system

1. Supplier's Access Point (AP)
2. Buyer's Access Point (AP)
3. Buyer's accounting system

Transition to 5-Corner Model (GST Mandate)

With the GST InvoiceNow Requirement, IRAS introduced a "5-corner model," adding IRAS as the fifth participant. This model involves automatic transmission of invoice data copies to IRAS via accredited APs for real-time GST compliance monitoring.

Key Features of InvoiceNow

• Structured Data Exchange: Uses standardized XML-based formats (Peppol BIS Billing 3.0 / PINT-SG) for automated processing.
• Real-Time GST Compliance: Automatic submission of invoice data to IRAS reduces manual GST reporting.
• Cross-border Interoperability: Supports international invoicing with other Peppol-connected countries.
• Enhanced Document Types: Recently added capabilities include electronic Purchase Orders and Invoice Responses, enabling end-to-end automation of procurement processes.

How to Use InvoiceNow SG

InvoiceNow simplifies the invoicing process by enabling businesses to send and receive structured e-invoices directly through the Peppol network. Here’s a comprehensive guide on how to get started and leverage InvoiceNow effectively.

• Ensure your business has a valid Unique Entity Number (UEN), which will serve as your Peppol ID.
• Choose an IMDA-accredited InvoiceNow-Ready Solution from the list of solution providers.
• Activate InvoiceNow through your chosen provider. Most providers handle the registration process, including setting up your Peppol ID.
• Select an Access Point Provider (AP) to facilitate invoice transmission on the Peppol network. You can find a list of approved Access Point providers on IMDA’s website.
•  If you already use accounting or ERP software, check if it is InvoiceNow-ready. For businesses without existing systems, free or subsidized software is available under IMDA's InvoiceNow Accelerate Program.
• Inform your suppliers and customers about your transition to InvoiceNow. Include your Peppol ID in all purchase orders.
• Use your InvoiceNow solution to create structured e-invoices in XML format compliant with Peppol BIS Billing 3.0 standards. Send invoices directly through the Peppol network to your customers’ Access Points.
• Receive invoices from suppliers in the same format, ensuring automated processing into your accounting system without manual intervention.

Requirements for Using InvoiceNow

To use InvoiceNow effectively, businesses must meet certain prerequisites:

• Possess a valid Unique Entity Number (UEN).
• Select an IMDA-accredited solution provider.
• Obtain a Peppol ID through Singapore’s Corppass platform.
• Ensure internal systems can generate structured invoice data compliant with Peppol standards.

For mandatory GST compliance from November 2025 onwards, newly incorporated companies voluntarily registering for GST must adopt an accredited solution immediately upon registration.

Benefits of Using InvoiceNow SG

Businesses adopting InvoiceNow experience numerous advantages:

• Cost Savings: Reduces invoicing costs by approximately S$8 per invoice by automating manual processes.
• Faster Payments: Electronic invoices are processed faster, improving cash flow significantly.
• Reduced Errors: Structured data exchange minimizes human errors common in manual entry.
• Improved Compliance & Audit Efficiency: Automated reporting simplifies GST compliance and reduces audit risks.
• Environmental Impact: Eliminates paper usage aligning with sustainability goals under Singapore’s Green Plan 2030.

Why Should Businesses Use InvoiceNow?

Beyond regulatory compliance, adopting InvoiceNow positions businesses strategically:

• Enhances operational efficiency through automation.
• Strengthens vendor relationships due to timely payments and accurate processing.
• Facilitates easier international trade with Peppol-connected countries.
• Prepares businesses proactively for future digitalization mandates.

Future of Electronic Invoicing in Singapore

Singapore plans progressive expansion of mandatory e-invoicing:

• By April 2026, all new voluntary GST registrants must comply.
• Future phases will likely extend mandatory adoption across all GST registrants.
• Enhanced integration with AI-driven reconciliation tools is anticipated.
• Enhanced integration with ASEAN countries adopting similar Peppol international standards (PINT), facilitating smoother regional trade transactions.
• Continuous improvements in technology infrastructure and interoperability standards as outlined in IMDA’s roadmap, detailed within their Technical Playbook.

Conclusion

InvoiceNow has evolved significantly since its voluntary introduction in 2019 into a robust nationwide e-invoicing framework integral to Singapore’s digital economy strategy. Initially facilitating voluntary B2B/B2G transactions using the Peppol standard, it now forms the backbone of mandatory real-time GST compliance under IRAS’s phased mandate starting May 2025.

Businesses must proactively adopt accredited solutions listed on IMDA’s portal to benefit from cost savings, faster payments, enhanced compliance capabilities, and seamless cross-border interoperability.

For official resources and further guidance:

• IMDA Official InvoiceNow Portal
• InvoiceNow Technical Playbook
• IRAS Official E-Tax Guide

Additional Resources for Onboarding: To support businesses in adopting InvoiceNow, IMDA provides several resources:

• SG Peppol Directory: Search for other businesses registered on the Peppol network to send and receive e-invoices seamlessly.
• Technical Playbook: A detailed guide covering system design, data extraction, and compliance requirements for implementing InvoiceNow.
• Training Workshops: Regular business briefings and technical workshops are conducted by IMDA to help businesses transition smoothly.