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

e-Invoicing in Singapore is called GST InvoiceNow.  It requires GST-registered businesses to submit structured invoice data to IRAS through the national InvoiceNow network (built on Peppol). Mandatory participation is being rolled out in phases, as first phase began on 1 November 2025 and will extend to all GST-registered businesses by 1 April 2031.

Key Takeaways

• GST InvoiceNow e-Invoicing requirement in Singapore applies based on business's annual supply size and GST registration type (voluntary/compulsory) in phases between 1 November 2025 to 1 April 2031. B2G invoicing is already live. 
• Businesses must use an IMDA-accredited InvoiceNow-ready solution or connect through an IMDA-accredited Access Point to transmit invoice data.
• The IRAS receives the invoices that must be in the SG PINT (Peppol BIS Billing 3.0) format for invoices under the 5-corner Peppol architecture.
• Populate all mandatory data fields accurately, as incomplete or invalid submissions are automatically rejected.
• SGD $1,000 transition grant opened on 1 July 2026 under GST InvoiceNow. It allows applicable SMEs to offset their e-Invoicing adoption costs while being able to use free software until March 2031.

What is e-Invoicing in Singapore (InvoiceNow)?

E-invoicing in Singapore, commonly referred to as InvoiceNow (in Singapore), is the direct system-to-system exchange of structured invoice data to IRAS through the GST InvoiceNow Peppol network. It makes Singapore the first non-European country to join the Peppol network. The buyer’s system automatically receives and processes invoice reducing manual intervention and supporting faster payment cycles. Hence, PDF or OCR formatted invoices won't work as e-invoices. 

Businesses participating in InvoiceNow use a Peppol ID, which functions as a digital address to route invoices correctly through the network.

Inland Revenue Authority of Singapore (IRAS) released the official e-Tax Guide on the adoption of the GST InvoiceNow requirement on 7 March 2025, providing detailed guidance and additional information for businesses. On the other hand, the Infocomm Media Development Authority (IMDA) governs the InvoiceNow network and provides accreditation.  

Singapore e-Invoice Implementation Timeline

As announced by IRAS on 26 February 2026, the GST InvoiceNow requirement will be implemented progressively for all GST-registered businesses under an updated phased timeline, as follows-

Note: For these implementation phases, “total annual supplies” refers to the total value of standard-rated, zero-rated, and exempt supplies made in all prescribed accounting periods ending in calendar year 2025. IRAS has also stated that GST-registered businesses registered before 2026 will be informed of their mandatory implementation date by mid-2026, while early adoption remains encouraged.

Who must comply with Singapore's GST InvoiceNow mandate? 

GST-registered businesses fall in the scope of the GST InvoiceNow initiative. Several key aspects of e-Invoicing aim at enhancing tax administration efficiency and compliance for these taxpayers. Transactions subject to e-Invoice Singapore include:

• 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.

Note: For point-of-sale supplies and petty cash purchases, businesses have the option to aggregate them before transmitting the data to IRAS without having to do it individually.

E-Invoicing Exemptions in Singapore

• 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 for imported services.
• Deemed supplies
• Non-reportable purchases (e.g., blocked input tax items)
  

B2G e-Invoicing in Singapore

Business-to-Government (B2G) e-invoicing is already live in Singapore. The authority has made InvoiceNow the default e-invoice submission channel for all government vendors. If you supply goods or services to a public sector entity, you must be on the Peppol/InvoiceNow network to invoice them. The portal is Vendors@Gov (vendors.gov.sg), administered by the Accountant-General's Department (AGD). It is separate from the phased GST InvoiceNow Requirement. 

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 specialised accounting and finance solutions that support InvoiceNow.
2. Standardised 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. 

What is Singapore's Peppol 5-Corner Model?

The standard Peppol framework uses four corners. Singapore adds a fifth. 

• Corner 1 is Seller: Generates the invoice in their ERP or accounting system
• Corner 2 is Seller's Access Point: Validates and transmits the invoice via the Peppol network
• Corner 3 is Buyer's Access Point: Receives and delivers the invoice to the buyer
• Corner 4 is Buyer: Receives the structured invoice directly into their finance system
• Corner 5 is IRAS: Under the GST InvoiceNow Requirement, a copy of the invoice data is simultaneously transmitted to IRAS for tax administration acting as Singapore's Continuous Transaction Control (CTC) layer sitting on top of the standard Peppol exchange.

For businesses not subject to the GST InvoiceNow Requirement, routing remains peer-to-peer between Access Points. SGNIC maintains the central directory for routing.

Singapore e-Invoice Requirements

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

1. 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). Check the IMDA website for the current list of InvoiceNow-Ready Solution Providers (IRSPs). 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.

2. 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 based on their UEN, and ensure business details are accurately listed in the SG Peppol Directory. 

For newly incorporated companies applying for voluntary GST registration from 1 November 2025 and 1 April 2026, obtaining a Peppol ID is a mandatory precondition before applying to IRAS.

3. 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, invoice type code and document UUIDs
• Precise GST amounts, rate (9%) and standardised GST category codes (e.g., SR, ZR, SRCA-S, TXCA, TXNA)
• Total invoice amount with and without GST
• 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.

4. 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).

5. 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).
• e-Invoice Archiving for 5 years: Businesses must retain invoice data for at least 5 years from the end of the relevant accounting period under the GST Act. IRAS retains its copy in line with its data management policies and the Personal Data Protection Act (PDPA). Your InvoiceNow-Ready Solution must track and store the date and time of submission, submission status, and the IRAS Acknowledgement ID for every transmission.

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.

How to get GST InvoiceNow Transition Grant

All you have to do is check your eligibility and grant quantum at imda.gov.sg/invoicenowgrants, open since 1 July 2026. The below table helps you with details of support and eligibility. Submit your application through the IMDA grants portal with your UEN, InvoiceNow-Ready Solution details, and supporting documents. 

Following benefits are given by the IRAS and IMDA to ease the adoption of e-invoicing-

How to get started with InvoiceNow in Singapore? 

Here is how businesses can adopt to GST InvoiceNow mandate:

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 customised 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' standardised GST category codes (as listed in Annex E of the IRAS e-Tax Guide). Ensure all relevant transactions are accurately categorised 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/XML files provided by IRAS with the IMDA's online validation tool (Validex), 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.

Penalties and Consequences of Non-compliance

The consequences differ depending on which phase you fall under.

Voluntary GST registrants (Those starting from 1 November 2025 and 1 April 2026):

As per Section 9 read with the First Schedule of the GST Act 1993, any non-compliance with the GST InvoiceNow Requirement is a breach of a condition of voluntary GST registration. So, the IRAS may revoke your GST registration. 

Existing GST-registered businesses (Those starting from 1 April 2028 to 1 April 2031):

No particular penalty defined under the law as of March 2026. However, the general GST Act penalty provisions under Part 9 (ss. 58–67) continue to apply to GST compliance broadly.

Invoice data errors:

If invoice contains errors upon transmission, IRAS's Voluntary Disclosure Programme applies. Errors disclosed within the grace period may qualify for penalty waiver or reduction.

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. We are a global e-invoicing platform providing local SEA entity support with presence in 50+countries including Malaysia and serving 5000+ global enterprises. Here's how it can assist:

• Seamless Integration: ClearTax’s platform integrates effortlessly with existing accounting and ERP systems such as SAP, Oracle, Microsoft Dynamics, NetSuite, Xero, QuickBooks, Sage Intacct and more.
• 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, SG PINT validation, and transmission of e-invoices via the InvoiceNow network to the IRAS, 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 SEA local support for smooth onboarding and continued assistance.

Conclusion

The Singapore government’s e-invoicing mandate, built on the InvoiceNow network powered by the global Peppol standard, marks a major step in modernising 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.