The Inland Revenue Authority of Singapore (IRAS) has released further clarifications regarding the mandatory onboarding of GST-registered businesses onto the InvoiceNow network, confirming that specific implementation dates for GST groups and divisions will be communicated at a later stage.
This update published on 9 March, provides critical technical guidance for compliance with the national e-invoicing framework ahead of the final 1 April 2031 deadline.
Phased Onboarding and Turnover Computation
IRAS has confirmed that a business’s applicable onboarding phase will be determined by the total value of supplies made during all prescribed accounting periods ending in the calendar year 2025. For businesses whose 2025 records do not cover a full year—such as newly registered entities—the tax authority permits extrapolation. In such cases, businesses may annualize their total supplies based on the number of days covered by their filed accounting periods to establish their correct onboarding tier.
Deferred Timeline for Complex Structures
In a significant move impacting corporate groups, IRAS stated that the implementation cut-off dates for both new and existing GST groups and GST divisions will be communicated later. This deferral suggests that the tax authority acknowledges the technical complexities involved in consolidating multi-entity or divisional transaction data under a single GST registration. Until further notice, these entities remain subject to the general 2031 mandate but are exempt from the specific phase-in schedules applicable to standard single-entity registrants.
Credit Note Handling and Data Submission
Addressing a common practical concern regarding adjustments, IRAS clarified the treatment of credit notes. Recipients of credit notes from suppliers are required to receive, validate, and accept the document within their InvoiceNow-Ready Solution. Subsequently, businesses must submit this credit note data to IRAS.
However, IRAS has provided an alternative compliance pathway to mitigate double-reporting risks. Instead of transmitting the standalone credit note data, businesses may submit the revised purchase invoice data—reflecting the adjustment made by the credit note—directly to IRAS. This flexibility allows taxpayers to align their invoicing records with their actual financial post-adjustment position, reducing reconciliation friction between accounting systems and tax filings.
Business Continuity and API Disruptions
Recognizing the dependency on digital infrastructure, IRAS has outlined contingency measures for Application Programming Interface (API) service disruptions. In the event of a system outage, the Comptroller may grant extensions for GST filing or invoice data submission deadlines.
Crucially, IRAS emphasized that while filing extensions may be granted, the underlying responsibility for data integrity remains with the business. Taxpayers remain accountable for ensuring the complete submission of all required invoice data to IRAS once the service is restored. Businesses are advised to maintain internal logs of transactions during any outage period to facilitate complete and accurate back-submissions, thereby avoiding potential penalties for non-compliance despite technical failures.
These updates reinforce the government’s commitment to a phased, pragmatic transition toward full digital reporting, while placing the onus on businesses to maintain robust system redundancies and reconciliation protocols.
Source: IRAS website, 9 March 2026