E-Invoicing in Singapore

The GST InvoiceNow Requirement represents a significant upgrade to Singapore's GST environment, marking a decisive move toward real-time tax reporting and a fully digital tax system. This is achieved by expanding the existing Peppol InvoiceNow network from a traditional four-corner model into a five-corner framework.

The core change is the introduction of a mandate that GST-relevant invoices must be transmitted not only to the trading partner, but also directly to the Inland Revenue Authority of Singapore (IRAS), establishing IRAS as the fifth corner in the exchange.

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 all new voluntary GST registrants. 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 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.

All GST-relevant invoices, irrespective of their original transmission method, must first be transformed into the PINT SG format and encapsulated in an SBDH (Standard Business Document Header) envelope before submission to IRAS. While B2B invoice exchange continues through the Peppol network using the Peppol PINT SG format, the submission to IRAS is executed via a direct XML API. Only IMDA-accredited Access Points are authorised to handle this final step of submitting invoice data to the tax authority.