E-Invoicing in Singapore

The GST InvoiceNow Requirement represents a significant upgrade to Singapore’s GST environment, moving the country toward more structured digital GST reporting and a more fully digital tax system. It builds on Singapore’s existing Peppol-based InvoiceNow network and extends the traditional four-corner e-invoicing model into a five-corner framework.

The core change is the introduction of an additional reporting flow to the Inland Revenue Authority of Singapore (IRAS). In-scope GST invoice data must be transmitted to IRAS through InvoiceNow-ready solutions, while buyer-supplier invoice exchange can continue through the Peppol InvoiceNow network where applicable. This establishes IRAS as the fifth corner in the exchange, without turning Singapore into a clearance model.

The requirement is being introduced progressively. Voluntary submission opened on 1 May 2025. Mandatory submission began on 1 November 2025 for companies that register for GST voluntarily within 6 months of incorporation, and extended on 1 April 2026 to businesses applying for voluntary GST registration on or after that date, regardless of incorporation date or business structure. Future phases apply from 1 April 2028 to new compulsory GST registrants and existing GST-registered businesses with annual supplies up to S$200,000, then progressively extend to existing GST-registered businesses with annual supplies up to S$1,000,000 from 1 April 2029, up to S$4,000,000 from 1 April 2030, and above S$4,000,000 from 1 April 2031.

In-scope GST invoice data must be prepared in the required format before submission to IRAS. B2B invoice exchange continues through the Peppol InvoiceNow network using the applicable Peppol / PINT SG format, while the IRAS reporting flow requires structured invoice data submission through the InvoiceNow framework. Only authorised InvoiceNow providers, including IMDA-accredited Access Points, can support the required connectivity for this reporting flow.