Singapore's Inland Revenue Authority commences Phase 2 of the GST InvoiceNow Requirement on 1 April 2026, requiring every new voluntary GST registrant — regardless of incorporation date or business structure — to transmit invoice data to IRAS via the IMDA-operated InvoiceNow Peppol network as a condition of voluntary registration.
GST InvoiceNow Requirement (GST InvoiceNow Requirement Phase 2 (1 April 2026) · WEF 1 April 2026)
On 1 April 2026, the Inland Revenue Authority of Singapore commences Phase 2 of the GST InvoiceNow Requirement: every new voluntary Goods and Services Tax registrant — regardless of incorporation date or business structure — must transmit invoice data to the Authority through the InvoiceNow network as a condition of voluntary registration. The conditions are set out on the IRAS GST InvoiceNow Requirement page and in the IRAS e-Tax Guide on Adopting GST InvoiceNow Requirement (Second Edition, published 9 March 2026).
Phase 2 extends a Phase 1 framework that began on 1 November 2025 for newly incorporated companies registering for GST voluntarily within six months of incorporation. Phase 2 widens the cohort to all new voluntary registrants of every age and structure.
The regulatory rationale, set out in the Phase 1 implementation announcement of 15 April 2024 and the Ministry of Finance Committee of Supply 2026 announcement of 26 February 2026, is twofold: digitalise tax administration through real-time invoice-data submission to enable faster GST audits and refunds; and amplify the network effect of Singapore's nationwide e-invoicing infrastructure — InvoiceNow — which the Infocomm Media Development Authority has operated as the country's Peppol Authority since 2019.
The mechanism is concrete. Voluntary GST registrants must engage an IMDA-accredited Access Point Provider, register a Peppol ID against their Unique Entity Number in the SG Peppol Directory, and enable the GST InvoiceNow submission feature in an IMDA-accredited InvoiceNow-Ready Solution. Invoice data transmits in the Peppol PINT-SG / BIS Billing 3.0 Universal Business Language format, with validation checks including detection of wrongful GST charges from non-registered suppliers.
The RegLegBrief Specialist Panel considered the IRAS GST InvoiceNow Requirement page alongside the e-Tax Guide (Second Edition, 9 March 2026), the Ministry of Finance Committee of Supply 2026 announcement of 26 February 2026, the IRAS Phase 1 implementation announcement of 15 April 2024, and the IMDA InvoiceNow programme description. Together these documents establish the Singapore architecture: IRAS as data recipient, IMDA as the network operator, and Peppol as the international interoperability anchor.
The Specialist Panel reviewed the international cohort and finds three converging tracks. The European Union's VAT in the Digital Age (ViDA) Directive, adopted in March 2025, mandates structured e-invoicing for intra-EU business-to-business transactions from July 2030 with digital reporting obligations from 2028. Italy's Sistema di Interscambio — operating since 2019 — is the longest-running B2B clearance system in Europe and serves as the ViDA benchmark. France launches its mandate on 1 September 2026 for large and intermediate enterprises, with small enterprises following from September 2027.
Read against the broader supranational context, the Singapore model aligns with the OECD's Tax Administration 3.0 programme and the OECD's January 2026 report on Digital Continuous Transactional Reporting for Value Added Tax; that report finds that close to forty per cent of tax administrations across fifty-eight surveyed jurisdictions can already prefill VAT returns thanks to electronic invoicing systems. The Specialist Panel notes that Singapore's Peppol-based, network-mediated architecture diverges from the centralised-clearance model favoured by Italy and France in favour of an interoperability-first design.
The Phase 2 commencement directly engages new voluntary Goods and Services Tax registrants under the Goods and Services Tax Act 1993, public accountants registered with the Accounting and Corporate Regulatory Authority advising on voluntary registration, members of the Institute of Singapore Chartered Accountants advising on tax compliance, IMDA-accredited InvoiceNow-Ready Solution Providers offering accounting and finance software, IMDA-accredited Access Point Providers operating Peppol nodes, and the in-house enterprise resource planning teams of Singapore-incorporated companies electing voluntary GST registration.
The operational delta is precise: voluntary GST registration applications submitted on or after 1 April 2026 may be rejected if the applicant has not adopted InvoiceNow. Overseas entities under the Overseas Vendor Registration Pay-only and full regimes, and businesses liable to register only because of the Reverse Charge regime, remain excluded from the GST InvoiceNow Requirement.
Second-order consequences include cash-flow timing changes from faster GST refunds, potential audit-cycle compression as IRAS receives near-real-time invoice data, and onboarding cost recovery through the Productivity Solutions Grant of up to S$30,000 for IT solutions including InvoiceNow-Ready Solutions.
The GST InvoiceNow Requirement Phase 2 takes effect on 1 April 2026. Voluntary registrants should secure an IMDA-accredited InvoiceNow-Ready Solution or engage an Access Point Provider, register a Peppol ID against their Unique Entity Number, and enable the GST InvoiceNow submission feature before lodging their voluntary registration application. The expansion to all GST-registered businesses follows from 1 April 2028 to 1 April 2031, phased by annual turnover. This regulatory development is preserved and cited by RegLegBrief at reglegbrief.com/cite/RLB-SG-2026-00052.