InvoiceNow GST E-Invoicing Singapore: 2026 Requirements and Timeline

If your company is GST-registered in Singapore, you are almost certainly required—or soon will be—to transmit invoice data to IRAS using the InvoiceNow network. The phased mandate was announced at the Ministry of Finance Committee of Supply Debate 2026, and all GST-registered businesses must onboard the network progressively from April 2028 to April 2031. What started as a voluntary, early-adopter programme is now a compliance requirement built on the international Peppol standard, and it touches every corner of your finance workflow: how you raise invoices, how you record purchases, and what data you send to the tax authority.

Who this matters to

• GST-registered companies of every size in Singapore, since the mandate eventually covers all of them except the exempted categories.
• Newly incorporated companies and any business considering voluntary GST registration, as InvoiceNow adoption is already a condition of registration.
• Finance, accounts-payable and accounts-receivable teams who raise, receive and record invoices day to day.
• Directors and business owners responsible for GST filing and record-keeping compliance.
• Businesses still on PDF or paper invoicing that will need to choose an accredited solution and connect to the network.

What InvoiceNow is and why the government is making it mandatory

InvoiceNow is Singapore's nationwide e-invoicing network based on the Peppol standard; introduced by the Infocomm Media Development Authority (IMDA) in 2019, it enables businesses to send and receive invoices in a structured digital format. Unlike a PDF sent by email, an InvoiceNow transaction is a structured XML file routed system-to-system through IMDA-accredited access points.

GST InvoiceNow builds on this by requiring businesses to transmit structured invoice data to IRAS for GST reporting, introducing a 5-corner model that includes the tax authority. When you issue or receive an invoice on the network, a copy of the transaction data flows automatically to IRAS. This is the shift the government calls "continuous transaction controls" (CTC): instead of reporting only summary GST totals every quarter, IRAS will receive granular, real-time data on each invoice you issue and every eligible purchase you make.

There are currently over 63,000 businesses on the InvoiceNow network utilising a variety of InvoiceNow services offered by accredited service providers. The mandate is designed to reduce manual processing, improve accuracy, shorten payment cycles, and make GST audits faster by giving IRAS structured data up front.

Who must comply and when: the phased timeline through April 2031

The timeline is split by registration type and annual turnover. Three groups are already in scope as of mid-2026:

• Since 1 November 2025, newly incorporated companies that voluntarily register for GST have been required to transmit invoice data to IRAS via the InvoiceNow network.
• From 1 April 2026, all new voluntary GST registrants are required to submit their invoice data directly to IRAS via the InvoiceNow network, regardless of their incorporation date or business structure. For new voluntary registrants, InvoiceNow adoption is now a condition of GST registration; IRAS may reject or delay applications if the requirement is not met.

The remainder of the roll-out targets existing GST-registered businesses in five revenue bands, determined by total annual supplies (standard-rated, zero-rated and exempt) in all prescribed accounting periods ending in calendar year 2025:

Effective date	Businesses in scope
1 April 2028	All new compulsory GST registrants, and existing businesses with annual taxable supplies ≤ S$200,000
1 April 2029	Existing GST-registered businesses with total annual taxable supplies up to S$1 million
1 April 2030	Existing GST-registered businesses with total annual taxable supplies up to S$4 million
1 April 2031	All remaining GST-registered businesses in Singapore

IRAS will inform GST-registered businesses that were registered before 2026 of their respective mandatory implementation date by mid-2026; in the meantime, existing GST-registered businesses may self-help and use the Excel calculator to determine their applicable implementation date. The calculator is published on the IRAS GST InvoiceNow Requirement webpage.

The following groups of businesses will be exempted: overseas entities (including Overseas Vendors registered under the OVR regime) and businesses registered under the Reverse Charge regime. If you are a local Singapore entity with a GST registration number, you are in scope.

What data you must transmit and when it is due

Businesses are required to transmit to IRAS data on the following transactions that are reported in the GST return: standard-rated and zero-rated supplies (sales), and standard-rated and zero-rated purchases on which input tax is or will be claimed. Both sales and purchase invoices must flow through the network.

The invoice data drawn from your tax invoices, simplified tax invoices, receipts with serial numbers, debit notes and credit notes must include supplier and customer details, GST registration numbers or UENs, invoice numbers, dates, line-item descriptions, quantities, amounts, and specific GST treatment codes (SR for standard-rated, ZR for zero-rated, ES for exempt, TX-CA for customer accounting). Foreign-currency invoices must show the Singapore-dollar equivalent.

Invoice data must be transmitted to IRAS by the earlier of the date on which you file your GST return or the filing due date for that return. If your GST return for January–March 2026 is due on 30 April 2026 and you file early on 20 April, your invoice data for that period must be transmitted no later than 20 April. If you file late, the due date is still 30 April.

Not every transaction goes into the system. Reverse-charge supplies and purchases, exported goods without actual sales, and internal transfers between head office and branch are excluded. For point-of-sale supplies and petty-cash purchases, businesses may aggregate transactions before transmission.

The two methods of transmission: Peppol invoices and solution-extracted data

IRAS and IMDA have designed two submission methods, and which you use depends on whether your trading partners are also on the network.

Peppol submission method: In the Peppol submission method, a copy of the Peppol invoice data is automatically transmitted to IRAS when the Peppol invoice is routed from the supplier to the customer through the InvoiceNow network. If both you and your customer have Peppol IDs, the invoice flows directly between your accounting systems in structured format, and IRAS receives the same data simultaneously. This is the cleanest and most automated approach.

Solution-extracted submission method: In the solution-extracted submission method, a copy of the solution-extracted invoice data is automatically extracted from the InvoiceNow-Ready Solution and transmitted to IRAS regularly (e.g. daily or weekly). If your customer is not on InvoiceNow—for example, a consumer or a business not yet onboarded—you still issue the invoice in your normal workflow, but your accounting system extracts the data and sends it to IRAS separately.

In practice, most businesses will use a hybrid of both: Peppol invoices for trading partners on the network and solution-extracted data for everyone else. Your IMDA-accredited InvoiceNow-Ready Solution Provider handles the technical routing.

How to get onto the InvoiceNow network

Joining the network requires three elements: a Peppol ID, connection to an IMDA-accredited access point, and an InvoiceNow-Ready Solution that can transmit data to IRAS.

Step one: choose an InvoiceNow-Ready Solution Provider (IRSP) or Access Point Provider (AP). Check if your preferred solution is listed on IMDA's accredited InvoiceNow-Ready Solution Providers (IRSP) list. Many off-the-shelf accounting packages—including Xero and a range of local and regional ERP systems—are already accredited. If you use an off-the-shelf solution, the IRSP typically bundles both the software and the access-point connection.

If you run an in-house or customised enterprise system, get in touch with an IMDA-accredited Access Point Provider (AP) to get connected to the InvoiceNow network; approach your AP to register your business in the SG Peppol Directory with your UEN and obtain your Peppol ID. The AP acts as the secure gateway, handling message routing and ensuring compliance with Peppol standards.

Step two: register for a Peppol ID. The Peppol ID assigned to Singapore businesses on InvoiceNow is based on the Unique Entity Number (UEN). Your IRSP or AP will register your company in the centralised SG Peppol Directory, which is managed by IMDA. You will need CorpPass access to complete the know-your-customer process.

Step three: enable the GST InvoiceNow submission feature. Enable the GST InvoiceNow submission feature so that you can transmit invoices directly from your InvoiceNow-Ready Solution to IRAS; contact your IRSP if you need assistance. For businesses using in-house systems, approach your AP to ensure that your solution is connected to IRAS and that the GST InvoiceNow submission feature is enabled so that you can transmit invoices directly from your in-house enterprise Solution to IRAS; contact your AP if you need assistance. The connection is made via API.

Allow 3 to 12 months for system connection to IRAS, though the entire process for system connection and testing can be accomplished in as little as 3 months, with most businesses fully onboarded within a year. Start early if your deadline is January 2027 or sooner.

Financial support and free solution packages available until March 2031

The government has committed transitional funding to keep costs manageable, particularly for SMEs.

To ease onboarding and encourage early adoption of InvoiceNow, the Government will introduce transitional funding to offset onboarding costs, ranging from up to $1,000 for small and medium-sized enterprises (SMEs) to up to $5,000 for larger businesses. Details on eligibility and application procedures will be released by IMDA and IRAS in due course.

SMEs can also tap on InvoiceNow-Ready Solutions for free, from now until March 2031. The current free-of-charge (FOC) solution package for GST-registered businesses is available until 31 March 2027; IMDA and IRAS will introduce a new set of FOC solution packages for the period of 1 April 2027 to 31 March 2031. A list of IRSPs offering FOC packages is published on the IRAS website.

Businesses using IMDA-accredited InvoiceNow-Ready Solution Providers (IRSP) may be eligible to apply for the Productivity Solutions Grant (PSG) and receive up to $30,000 for IT solutions and equipment, including InvoiceNow-Ready Solutions. Check Enterprise Singapore's PSG portal for the current pre-approved vendor list and co-funding rates.

What this means for your bookkeeping, GST returns, and record-keeping obligations

InvoiceNow does not replace your existing GST compliance duties. You still prepare and file quarterly (or monthly) GST returns within the statutory deadline, you still maintain proper books and records for five years, and you still issue tax invoices that meet the requirements of the GST Act. What changes is the mechanism by which IRAS sees your transactions.

Because invoice data now flows to IRAS continuously, expect your GST audits to become faster and more data-driven. IRAS can pre-populate checks, cross-reference supplier and customer records in real time, and flag discrepancies—such as a non-GST-registered supplier charging GST—earlier in the cycle. Some InvoiceNow-Ready Solutions already include validation features that alert you when an invoice appears incorrect, reducing the risk of input-tax denials later.

If you file late or fail to transmit invoice data by the due date, IRAS has said it will take a "calibrated lenient approach" in the initial stages, focusing on education rather than immediate penalties. But the legislation is clear: not transmitting a required invoice is equivalent to failing to issue a tax invoice, and under Section 41 of the GST Act a failure to issue can incur a fine of up to S$5,000 per offence. For new voluntary registrants, non-compliance may result in revocation of GST registration.

From a practical workflow perspective, consider three changes. First, your accounts-payable and accounts-receivable teams will need to verify that counterparty Peppol IDs are correct before invoices can route. Second, if you currently aggregate certain low-value transactions only at month-end, you may need to bring that aggregation forward to meet the GST-return filing deadline. Third, currency conversions for foreign invoices must now produce a Singapore-dollar amount that IRAS can validate; agree your FX methodology with your tax adviser and document it clearly.

Common mistakes to avoid

• Assuming the mandate is years away. New voluntary registrants are already in scope, and onboarding can take up to twelve months, so a 2028 deadline still means starting soon.
• Treating InvoiceNow as a replacement for GST returns. You still file returns, issue compliant tax invoices, and keep records for five years.
• Forgetting purchase invoices. Both sales and eligible purchases on which input tax is claimed must flow through the network, not just your sales.
• Missing the transmission deadline. Invoice data is due by the earlier of your filing date or the return due date, which is easy to overlook if you file early.
• Leaving counterparty Peppol IDs unverified or applying an undocumented FX methodology for foreign-currency invoices.

How Steadbook can help

We help owner-managed businesses navigate GST compliance, configure InvoiceNow-ready accounting workflows, and liaise with accredited solution providers on your behalf. Our accounting and GST support covers the full picture, from GST filing services in Singapore to day-to-day accounting services in Singapore. If you would like to discuss your company's timeline or need support preparing for the mandate, visit our contact page or speak to your usual Steadbook adviser.

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