e-Invoicing in Singapore: Applicability, Limit, Guidelines & Implementation Date

The Inland Revenue Authority of Singapore (IRAS) announced the soft launch of e-invoicing in Singapore under the GST InvoiceNow Requirement, starting in May 2025, for voluntary early adoption. From 1 November 2025, compliance with this e-invoicing mandate will become mandatory for newly incorporated companies that voluntarily register for GST, with further phased implementation planned for all GST registered businesses.

This initiative requires GST-registered businesses to transmit invoice data directly to IRAS for tax administration purposes through Singapore's nationwide e-invoicing system, based on the international Peppol standard. 

All businesses under the scope must adopt e-invoicing solutions connected to the InvoiceNow network, enabling seamless data transmission to IRAS via API-enabled Access Point providers. This transition aims to streamline compliance, reduce manual efforts, and facilitate structured digital invoice processing.

Update (March 7, 2025)

IRAS released its first edition of the e-Tax Guide titled "Adopting GST InvoiceNow Requirement for GST-registered Businesses". This guide outlines compliance details for businesses adopting InvoiceNow. Download here

What is an e-Invoice in Singapore?

An e-Invoice in Singapore refers to an electronic invoice transmitted digitally through the InvoiceNow network, a nationwide e-invoicing platform based on the international Peppol standard. It facilitates seamless, structured, and automated data exchange between businesses' finance systems.

Singapore e-Invoice Implementation Timeline

Peppol e-invoicing Singapore requirement are supposed to apply to all GST-registered businesses in a phased approach as follows

Scope of GST InvoiceNow

The scope of the GST InvoiceNow initiative encompasses several key aspects aimed at enhancing tax administration efficiency and compliance among GST-registered businesses. Here's an overview:

1. Transactions Covered: GST-registered businesses are required to transmit invoice data to IRAS for specific transactions, including:
   • Standard-rated supplies (except supplies under reverse charge)
   • Zero-rated supplies
   • Standard-rated purchases for which input tax claims are made or will be made. However, this excludes reverse-charge purchases.
2. Point-of-Sale Supplies and Petty Cash Purchases: For these types of transactions, businesses have the option to aggregate them before transmitting the data to IRAS.
3. Exempted Transactions: Additionally, specific transactions are excluded from mandatory transmission:

• Deemed supplies
• Reverse charge supplies/purchases
• Non-reportable purchases (e.g., blocked input tax items)

Exemptions from the Singapore e-Invoicing

• Overseas Entities including Overseas Vendors: Parties that are registered under the Overseas Vendor Registration regime and overseas vendors are exempt from e-invoicing. Since they operate outside Singapore's jurisdiction, they are exempt from the GST InvoiceNow Requirement.
• Businesses Registered under the Reverse Charge Regime: Businesses operating under the Reverse Charge regime.

How is e-Invoice Singapore different from current Invoicing?

The implementation of GST InvoiceNow represents a significant shift in the invoicing process for GST-registered.

1. Digital Transmission: GST InvoiceNow requires businesses to transmit invoice data electronically to the Inland Revenue Authority of Singapore (IRAS) using InvoiceNow solutions and networks. This means moving to a fully digital process facilitated by specialized accounting and finance solutions that support InvoiceNow.
2. Standardized Format: InvoiceNow operates on the Peppol standard, ensuring that invoices are exchanged in a structured digital format for seamless data exchange and transmission. Accounting and finance solutions supporting InvoiceNow are configured to automatically generate invoices in the required format.
3. Two-Way Data Flow: Through the InvoiceNow portal, both sellers and buyers are required to input their sale and purchase data. 
4. Integration with IRAS: All information entered by buyers and sellers via the InvoiceNow portal is seamlessly integrated with the IRAS system. Once inputted, this data undergoes validation checks to ensure accuracy and compliance with tax regulations before being securely stored. 

Singapore e-Invoice Requirements

To comply with Singapore's GST InvoiceNow Requirement for GST-registered businesses, the following enriched criteria must be met:

Use of InvoiceNow-Ready Solutions

Businesses must adopt accounting and finance software classified as "InvoiceNow-Ready Solutions," accredited by IMDA and connected via IMDA-accredited Access Point Providers (APs). These solutions must adhere strictly to the Singapore Peppol BIS 3.0 or PINT-SG specifications, enabling structured digital invoicing in compliance with the international Peppol standard.

Mandatory Registration and Obtaining Peppol ID

GST-registered businesses must register for InvoiceNow through their InvoiceNow-Ready Solution Provider (IRSP) or AP, obtain a unique Peppol ID, and ensure their business details are accurately listed in the SG Peppol Directory. 

For newly incorporated companies applying for voluntary GST registration from 1 November 2025 (incorporated within six months prior to GST registration), obtaining a Peppol ID is a mandatory precondition before applying to IRAS.

Mandatory Data Elements (MDEs)

Submissions through InvoiceNow must include comprehensive Mandatory Data Elements as specified by IRAS, such as:

• Supplier and customer details including UEN and GST registration numbers (GSTNs)
• Invoice numbers, issue dates, and document UUIDs
• Precise GST amounts and standardized GST category codes (e.g., SR, SRCA-S, TXCA, TXNA)
• Transaction descriptions and currency codes (with SGD equivalents for foreign currency invoices)

Businesses must map internal tax codes to IRAS-approved GST category codes provided in Annex E of the IRAS e-Tax Guide. For aggregated submissions (e.g., POS or petty cash purchases), special entries like "POS" or "PCP" should be indicated clearly in relevant MDE fields.

Technical Compliance via API Integration

Businesses must ensure their chosen InvoiceNow-Ready Solutions are integrated with IRAS through API technology via IMDA-accredited Access Points. This integration facilitates real-time or regular automated transmission of invoice data to IRAS. Solutions should incorporate built-in validation checks using IRAS' Check GST Register API to detect wrongful GST charges from non-GST registered suppliers.

Bulk submissions via API are permitted with a maximum limit of 10 documents per submission package or a total data size not exceeding 10MB per package.

Timely Data Transmission to IRAS

The timing for transmitting invoice data to IRAS aligns strictly with the businesses' GST return filing schedules. Specifically, invoice data must be transmitted by the earlier of:

• The actual date on which the relevant GST return is filed; or
• The official filing due date of the relevant GST return.

The transaction date determining submission timing is defined as:

• For supplies: Invoice issue date or accounting posting date if no invoice is issued.
• For purchases: Either invoice issue date or accounting posting date (at the business's discretion).

Additional Compliance Points

• Foreign currency invoices must clearly state SGD equivalents using IRAS-approved exchange rates.
• Credit notes issued must follow original invoice submission methods and include references to original invoice numbers/dates.
• Advance payments require submission only upon issuance of formal tax invoices (not pro-forma invoices).

Major Stakeholders for e-Invoicing in Singapore

IRAS (Inland Revenue Authority of Singapore)

IRAS is the tax authority in Singapore responsible for administering taxes, including the Goods and Services Tax (GST). It oversees the collection of taxes and ensures compliance with tax laws and regulations.

IRAS would receive, validate and store the invoice data received from the supplies and buyers and would use it for tax assessment, compliance, and enforcement.

InvoiceNow Solutions

InvoiceNow Solutions refers to finance and accounting software or systems that enable the transmission of invoices between businesses via the InvoiceNow network. These solutions can be off-the-shelf software or customized enterprise resource planning systems connected to the InvoiceNow Network through the access point.

InvoiceNow Solutions will facilitate the transmission of invoice data from GST-registered businesses to InvoiceNow Network for tax administration purposes. 

InvoiceNow Network

The InvoiceNow Network is a nationwide e-invoicing network based on the international Peppol standard. It enables businesses to send and receive invoices in a structured digital format, improving efficiency and reducing the need for manual processing.

The InvoiceNow Network is the infrastructure through which invoice data is transmitted from InvoiceNow solutions to IRAS system. 

Peppol

Peppol, which stands for Pan-European Public Procurement On-Line, is an international standard for electronic document exchange, particularly focused on e-invoicing. It provides a set of specifications and protocols for the secure and standardized exchange of business documents, such as invoices, between trading partners.

The InvoiceNow Network is based on the Peppol standard, enabling businesses to exchange invoices in a structured digital format. Peppol ensures interoperability and compatibility between different systems and allows businesses to transmit invoice data securely and efficiently to IRAS.

IMDA (Infocomm Media Development Authority):

IMDA is a statutory board in Singapore that oversees the development and regulation of the infocomm media sector. It promotes the adoption of digital technologies and supports initiatives to enhance Singapore's digital capabilities.

IMDA has collaborated with IRAS and other businesses to promote the adoption of InvoiceNow among GST-registered businesses. It provides support, resources, and grants to encourage businesses to adopt InvoiceNow Solutions. IMDA also oversees the InvoiceNow Accelerate program, which offers free InvoiceNow services to newly incorporated businesses.

Other Important Points Regarding GST InvoiceNow

• Businesses are responsible for ensuring compliance with invoicing requirements.
• The adoption of GST InvoiceNow does not exempt businesses from mandatory record-keeping obligations for GST-registered businesses.
• Invoice data transmitted to IRAS will be stored in IRAS' system with adequate support
• Grants such as the InvoiceNow Transaction Bonus and LEAD Connect and Transact Grant are available for businesses willing to early adopt GST InvoiceNow

How Businesses Should Prepare for Adoption of GST InvoiceNow Solutions?

It's important for businesses under the e-invoicing Singapore to be compatible with the GST InvoiceNow Requirement. To ensure a smooth transition, follow these steps:

1. Check Solution Compatibility: Verify if your existing accounting or finance software is listed on IMDA’s accredited InvoiceNow-Ready Solution Provider (IRSP) list. If you don't currently have a compatible solution, consider adopting an accredited free or paid solution with InvoiceNow capabilities.
2. Engage Accredited Providers: For businesses using customized or in-house solutions, engage an IMDA-accredited Access Point (AP) provider to establish secure connectivity to the InvoiceNow network and IRAS via API technology. Clearly differentiate between IRSPs (who provide accounting software) and APs (who enable network connectivity), and understand their respective roles.
3. Obtain Peppol ID and Register: Work with your selected IRSP or AP provider to register your business in the SG Peppol Directory using your Unique Entity Number (UEN) and obtain your Peppol ID, which is essential for sending and receiving e-invoices.
4. Map Internal Tax Codes: Clearly map your internal tax codes to IRAS' standardized GST category codes (as listed in Annex E of the IRAS e-Tax Guide). Ensure all relevant transactions are accurately categorized according to IRAS requirements.
5. Activate GST InvoiceNow Submission Feature: Activate the GST InvoiceNow Submission feature within your InvoiceNow-ready solution.Conduct thorough testing of invoice data transmission to IRAS, including validation checks using Schematron files provided by IRAS, ensuring compliance with mandatory data elements (MDEs).
6. Allow Sufficient Lead Time: Allocate adequate time (approximately 3-12 months) for comprehensive system integration, API connectivity setup, internal staff training, and extensive testing before mandatory implementation deadlines.
7. Establish Business Continuity Plans: Prepare robust contingency plans to handle potential API service interruptions or other unforeseen technical issues, ensuring continuous compliance with GST InvoiceNow requirements.

Potential Challenges of Implementing e-Invoicing in Singapore

E-invoicing is an incredibly efficient process, but it does present certain challenges due to its technical nature, which is more complex than traditional invoicing methods.

1. Adoption Hesitation: Small and medium enterprises (SMEs) may be reluctant to adopt e-invoicing due to perceived high costs and changes to established workflows.
2. Integration Complexity: Businesses using custom or legacy accounting systems may face challenges in integrating InvoiceNow with their existing setups.
3. Training Requirements: Staff need training on using e-invoicing systems, which can be time-consuming and costly.
4. Data Security Concerns: Ensuring data security and compliance with privacy laws may pose challenges for businesses.
5. Vendor Readiness: Not all suppliers and customers may be ready or willing to adopt the InvoiceNow network voluntarily in the early phase
6. Initial Setup Costs: While grants are available, businesses may still find the initial costs for implementation and system upgrades burdensome.

How ClearTax Can Help Your Business with e-Invoicing in Singapore

ClearTax offers robust e-invoicing software in Singapore that is tailored to meet the needs of businesses transitioning to e-invoicing in Singapore. Here's how it can assist:

• Seamless Integration: ClearTax’s platform integrates effortlessly with existing accounting and ERP systems.
• Compliance Assurance: It ensures compliance with Singapore’s e-invoicing and GST regulations, reducing the risk of errors and penalties.
• Maximum Automation: ClearTax e-invoicing software  automates the generation, validation, and transmission of e-invoices via the InvoiceNow network, reducing manual effort.
• Dedicated Online Portal: Features an intuitive online portal to issue, receive, track, and manage e-invoice and generate detailed reports.
• Training & Support: Provides user-friendly training modules and dedicated support for smooth onboarding and continued assistance.

Benefits of GST InvoiceNow

1. Streamlined Processes: InvoiceNow enables direct transmission of e-invoices in a structured data format, reducing manual work in sending, receiving, and recording invoices. 
2. Reduced Errors and Costs: By automating invoice processing, InvoiceNow reduces the likelihood of errors in invoicing and payment. This leads to fewer rectification costs and improves overall efficiency.
3. Improved Cash Flow Management: Quicker invoice processing and payment facilitated by InvoiceNow help businesses manage their cash flow more effectively. 
4. Enhanced Compliance: By transmitting invoice data directly to IRAS, businesses streamline compliance processes and reduce the risk of errors in tax reporting.
5. Access to Value-Added Services: InvoiceNow solutions may offer additional services, such as built-in checks for incorrect GST charges from suppliers, helping businesses maintain compliance and optimise their operations

Additional benefits for GST-registered businesses for adopting InvoiceNow solutions 

1. Utilizing InvoiceNow solutions for transmitting invoice data to IRAS reduces compliance efforts for GST-registered businesses.
2. Improved risk analysis by IRAS may lead to fewer audits for businesses, with shorter audit processes and quicker issue resolution.
3. Businesses with lower risk profiles may receive GST refunds sooner.
4. InvoiceNow solutions offer value-added services, including built-in checks to identify invoices erroneously charging GST, thereby simplifying tax compliance.

Conclusion

The Singapore government’s e-invoicing mandate, built on the InvoiceNow network powered by the global Peppol standard, marks a major step in modernizing tax administration for GST-registered businesses. By mandating e-invoice Singapore adoption, the Singapore government has ensured seamless integration of tax compliance into daily business operations, aligning with global trends in digital tax systems.

Early adopters can benefit from grants like the Productivity Solutions Grant and LEAD Connect & Transact Grant, helping offset costs reducing cost of implementation. ClearTax can help businesses for smooth transitions, enabling compliance with the Singapore e-invoicing IRAS requirements.