How to Submit e-Invoices to the IRAS Portal?

Singapore has announced a nationwide e-invoicing mandate for GST-registered businesses starting November 2025. Understanding how to submit e-invoices to the IRAS portal is critical for businesses to comply with the regulations while streamlining their invoicing processes. 

This guide will walk you through the process of e-invoicing in Singapore, including the requirements for connecting to the InvoiceNow network, steps to submit e-invoices to IRAS portal, when to submit the data, and mandatory data fields to be submitted.

e-Invoicing in Singapore

GST InvoiceNow or GST e-invoicing initiative mandates GST-registered businesses to transmit invoice data to the Inland Revenue Authority of Singapore (IRAS) via InvoiceNow solutions, which operate on the Peppol network. 

The government is progressively implementing this requirement, starting with new voluntary GST registrants from 1 November 2025, and expanding to all new voluntary GST registrants by 1 April 2026. A soft launch for early adopters begins on 1 May 2025.

This system is designed to streamline invoicing, enhance tax compliance, and align Singapore with global e-invoicing standards.

Requirements

• Newly incorporated businesses registering for GST voluntarily must comply with the e-invoicing requirement starting 1 November 2025. All new voluntary GST registrants must comply starting 1 April 2026.
• Businesses must use InvoiceNow solutions to send structured digital invoices to IRAS via the Peppol network containing all Mandatory Data Elements (MDEs).
• E-Invoices for  businesses-to-businesses (B2B) transactions are to be generated separately while petty purchases and Consumer (B2C) transactions can be consolidated.
• Invoice data for standard-rated and zero-rated supplies and input tax claims for standard-rated purchases must be transmitted to IRAS by the relevant GST filing deadlines.

InvoiceNow and Peppol: Their Roles in GST e-Invoicing Mandate

InvoiceNow and Peppol are different aspects of the GST e-invoicing mandate; however, they are closely interlinked.

InvoiceNow

InvoiceNow is a nationwide e-invoicing network in Singapore designed to facilitate efficient processing of invoices. It operates on the Peppol framework, an open international standard, enabling businesses to directly transmit e-invoices in a structured digital format across different financial systems.

InvoiceNow Solutions are IMDA pre-approved and certified finance and accounting tools the connect business systems with the Peppol network helping send or receiving e-invoices

The Singapore GST e-invoicing mandate requires GST-registered businesses to transmit e-invoices (invoicing data) to the IRAS using InvoiceNow solutions.

Role of InvoiceNow 

• Acts as the primary Peppol compliant e-invoicing network for transmitting invoices between businesses and the Inland Revenue Authority of Singapore (IRAS).
• Simplifies compliance with Singapore’s GST InvoiceNow Requirement by ensuring structured and secure invoice data transmission.

Peppol 

Peppol (Pan-European Public Procurement Online) is an internationally recognized e-document delivery framework that facilitates the seamless exchange of standardized electronic invoices. By connecting businesses through a single, unified network, Peppol enables interoperability across diverse accounting and ERP systems globally.

Role of Peppol in Singapore GST e-Invoicing

• Provides the underlying framework for InvoiceNow, ensuring compatibility and standardization
• Enables businesses in Singapore to connect to a global network for both local and cross-border e-invoicing

e-Invoicing Process in Singapore

Submitting e-invoices to IRAS involves the following key steps:

1. Invoice Creation: Generate invoices in your InvoiceNow-enabled accounting or ERP system.
2. Data Transmission: Once an invoice is finalized, it is transmitted through the Peppol network to IRAS via an API connection.
3. Verification and Storage: IRAS receives and securely stores the invoice data for tax compliance and auditing purposes.

Preparing to Submit e-Invoices

Before starting to transmit e-invoices to the government, it is necessary to align systems, processes, and people to ensure seamless integration and compliance. Here are the steps:

Step 1: Ensure InvoiceNow Enablement

Verify if your accounting or finance solution is Peppol-Ready by consulting the list on the IMDA website. Enterprises with proprietary systems should engage IMDA-certified Access Point (AP) providers to enable connectivity to the InvoiceNow network.

Step 2: Register for InvoiceNow

Approach your solution provider or AP to register your business in the SG Peppol Directory and obtain a Peppol ID.

Step 3: Connect Your Solution to IRAS

Ensure your InvoiceNow-enabled solution is integrated with IRAS’s system via API.

Step 4: Activate and Test Submission

Work with your solution provider to activate the feature for transmitting invoices to IRAS. Conduct end-to-end tests to ensure successful data transmission.

Steps to Submit e-Invoices to the IRAS Portal

Irrespective of the type of transaction being conducted and the parties involved the overall process for the submission of e-invoice to IRAS remains the same

1. Recording Transactions: Ensure all invoices (sales and purchases) are recorded in your InvoiceNow-enabled solution. For transactions outside the network, accurately input details like GST rate, taxable amount, and customer or supplier identifiers.
2. Generating the Submission File: The solution automatically generates the required submission file in the standard format, containing all Mandatory Data Elements (MDEs) 
3. Transmission to IRAS: Use your Access Point (AP) to transmit the data file to IRAS. The process may involve validation checks to ensure all required fields are complete and accurate.
4. Confirmation: After submission, you will receive a confirmation indicating that the invoice data has been successfully transmitted to IRAS.

Different Types of e-Invoice Submission to IRAS

There are four main types of submissions based on the nature of the transaction and the parties involved. The following table outlines the four primary types of e-invoice submissions to IRAS, their scenarios, and respective processes:

When to Submit e-Invoice Data to IRAS?

Invoice data must be transmitted to IRAS at the earlier of:

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

Example

If a company’s prescribed accounting period is from 1 January to 31 March, and:

• The GST return is filed on 20 April, and
• The filing due date is 30 April,

The invoice data must be transmitted to IRAS by 20 April if the return is filed on that date. Otherwise, the deadline is 30 April.

Mandatory Data Elements (MDEs)

Mandatory Data Elements (MDEs) are essential components that must be included in invoice data submissions to IRAS. These elements ensure that the transmitted data meets regulatory requirements and facilitates accurate tax administration. Key MDEs include the following

Supplier Details

• Supplier Name
• Supplier Unique Entity Number (UEN)
• Supplier Address (including postal code and country)
• Supplier GST Registration Number (GSTN)

Customer Details

• Customer Name
• Customer UEN (if applicable)
• Customer Address (including postal code and country)

Invoice Details

• Invoice Number
• Invoice Issue Date
• Invoice Type Code (e.g., standard invoice, credit note)
• Currency Code
• Total Invoice Amount (with and without GST)
• Amount Due for Payment

Tax Details

• GST Category Code (e.g., SR for standard-rated, ZR for zero-rated)
• GST Rate (e.g., 9%)
• GST Amount
• Taxable Amount

Conclusion

e-invoicing in Singapore leverages the InvoiceNow network and Peppol framework to enable seamless and structured transmission of invoice data directly to IRAS. To submit e-invoice data to IRAS, businesses use InvoiceNow-enabled solutions to securely record and transmit invoice data via the Peppol network, ensuring compliance with mandatory data requirements. The process includes API-based submission and confirmation from IRAS for accurate tax reporting.