What is the GST InvoiceNow Requirement?

The GST InvoiceNow Requirement is IRAS's mandate that GST-registered businesses transmit invoice data directly to IRAS via the InvoiceNow Peppol network, using InvoiceNow-Ready accounting or invoicing software. The rollout is phased: voluntary early adoption opened 1 May 2025, with mandatory phases running through to April 2031.

This is the deeper companion to the InvoiceNow overview — that page explains the network. This page explains the mandate.

Why it exists

GST is Singapore's largest indirect tax revenue. Today IRAS receives only aggregate quarterly numbers via the GST F5. Under the GST InvoiceNow Requirement, IRAS receives transaction-level invoice data as it happens — closer to a real-time GST data feed. The stated goals: faster anomaly detection, fewer filing errors, less manual GST data entry, and easier audits.

The full rollout timeline

| Date | Who is required | |---|---| | 1 May 2025 | Voluntary early adoption opens for any GST-registered business that wants to start ahead of the mandate (soft launch) | | 1 November 2025 | Newly incorporated companies (incorporated within 6 months before their GST registration application) that voluntarily register for GST | | 1 April 2026 | All new voluntary GST registrants, regardless of incorporation date or business structure | | April 2028 | Existing GST-registered businesses begin phasing in — IRAS phases by annual supply value, larger first | | April 2031 | All existing GST-registered businesses must comply |

The April 2031 endpoint was formally announced at Committee of Supply 2026 — before that, the existing-business phases were described qualitatively without a hard end-date.

Transitional funding

Government co-funding is available to offset onboarding costs:

Up to S$1,000 for small and medium-sized enterprises (SMEs)
Up to S$5,000 for larger businesses

SMEs can additionally use the Productivity Solutions Grant (PSG) to subsidise eligible InvoiceNow-Ready software. Free InvoiceNow services are also being offered to newly incorporated businesses to ease adoption.

What "adopting" actually means

To comply, a GST-registered business needs to:

Use an InvoiceNow-Ready solution. Either an accounting/ERP package on the IMDA list, or connect through an accredited Access Point Provider.
Send and receive invoices via the Peppol network using the PINT-SG syntax.
Transmit invoice data to IRAS. Your InvoiceNow-Ready solution handles this automatically — there's no separate IRAS portal step.

You still file your quarterly GST F5, but most of the data is already with IRAS.

What changes vs today

| Before | After | |---|---| | Invoice as PDF, emailed | Invoice as structured PINT-SG XML, routed via Peppol Access Points | | GST data entered manually into F5 | GST data pre-populates from invoice transmissions | | Errors caught at filing time | Errors flagged earlier — at point of capture | | Customer manually keys in your invoice | Customer's system receives the invoice as data |

How to prepare now

Check your current invoicing tool. Is it on IMDA's InvoiceNow-Ready list? If not, plan a switch.
Register your business's Peppol ID (your accredited Access Point Provider does this; it's tied to your UEN — your Unique Entity Number).
Confirm your software captures the mandatory data elements for PINT-SG — customer UEN, customer name, customer address — for every B2B invoice.
Decide whether to adopt early. Voluntary adoption from 1 May 2025 gives you a tested process before the mandate hits your phase.

InvoiceNow — InvoiceNow is Singapore's nationwide Peppol e-invoicing network.
Peppol / PINT-SG — Peppol is the international e-invoicing standard.
GST F5 — GST F5 is the quarterly GST return every GST-registered business in Singapore files with IRAS.
Tax invoice (Singapore) — A tax invoice is the document a GST-registered Singapore business issues so its GST-registered customer can claim input tax.

Sources

Last reviewed 29 May 2026. Verify any thresholds or dates against the official source above before relying on them.