E-invoicing in Singapore — InvoiceNow & Peppol BIS Billing 3.0.

Singapore is our home market. Guliel is bootstrapped from Singapore, and the Singapore GST tax invoice is one of the first document types we shipped. This page is the honest version of what InvoiceNow is, what it isn't, and where Guliel sits in the picture.

Peppol AP — landing later this year. Guliel generates the Singapore GST tax invoice today, including the Peppol BIS Billing 3.0 XML payload. What we don't yet do is transmit it through the Peppol network ourselves — Guliel is becoming a certified Peppol Access Point later this year. Until that's live, Singapore customers run the generated XML through their existing AP or the IMDA-listed access point of their choice. The document Guliel produces is the same one your AP would forward; only the last-mile delivery is different.

The short version

Singapore's national e-invoicing network is called InvoiceNow. It runs on the Peppol BIS Billing 3.0 standard and is administered by IMDA, with the Inland Revenue Authority of Singapore (IRAS) driving the GST-side rollout. The phased mandate runs from 2025 through 2031: new voluntary GST registrants first, then broader cohorts of GST-registered businesses over time.

If you sell B2B in Singapore, this is the format your invoices need to land in. PDF tax invoices remain valid for existing GST registrants right now, but the direction is unambiguous — structured e-invoicing is becoming the default, and the IRAS guidance keeps moving in that direction.

Mandate timeline

The InvoiceNow GST rollout is phased. Public IRAS guidance has set out the following:

• November 2025 — InvoiceNow data transmission becomes mandatory for newly incorporated companies that voluntarily register for GST within six months of incorporation.
• April 2026 — Mandatory for all new voluntary GST registrants.
• 2026 onwards — Further cohorts of existing GST-registered businesses are expected to be onboarded in waves through 2031, per IRAS' public phasing plan.

The framing in Singapore is gradual and pragmatic — IRAS has been explicit that existing registrants on PDF/email invoicing remain compliant for now. The shift is to give finance teams time to adopt without breaking anything.

Peppol BIS Billing 3.0 explained

Peppol BIS Billing 3.0 is the structured XML format InvoiceNow uses to move invoice data between trading partners and to IRAS. A few things to know:

• It is a standard, not a piece of software. Buyers and sellers each connect to the Peppol network through an Access Point. The Access Point is the on-ramp.
• The data model maps the standard tax-invoice fields — supplier, customer, GST registration numbers, line items, GST rates and amounts, totals — into a defined schema. That schema is what IRAS reads.
• A Peppol-compliant invoice is machine-readable first. The PDF you used to email out is now generated from the same source data, not the other way around.

If you've shipped goods or services in Singapore you already know the inputs — GST registration number, the 9% GST rate, supplier and customer details, line items, the "Tax Invoice" label. Peppol BIS just standardises how those inputs are transmitted.

How Guliel handles it

Honest scope. Guliel covers the document-compliance side — generating Singapore GST tax invoices that match IRAS' mandatory field list and producing the structured Peppol BIS Billing 3.0 payload from the same source data. Specifically:

• Singapore Tax Invoice as a first-class document type — "Tax Invoice" label, supplier name and GST registration number, sequential invoice number, customer details, line items, 9% GST itemised, total including GST.
• Simplified tax invoice for transactions up to SGD 1,000 (including GST), per IRAS rules.
• Peppol BIS Billing 3.0 output alongside the PDF, generated from the same invoice source — no duplicate data entry.
• <1 second issuance once the invoice is composed.
• GST report by jurisdiction in the reporting module to support filing.

What Guliel does not do:

• Guliel is not a Peppol Access Point. We produce the compliant document; transmission to IRAS via the Peppol network goes through your chosen IMDA-approved Access Point provider. We're upfront about this — we're an invoicing and finance-ops platform, not a network operator.
• Guliel is not a full accounting suite. If you need full double-entry, audited GST returns and statutory accounts, you'll pair Guliel with Xero, QuickBooks, or your accountant's preferred ledger. We're the operating layer above invoicing, expenses, suppliers, logistics, reporting and automations — see /invoicing for the document scope.

For SG SMBs and freelancers running cross-border work, the practical workflow looks like: issue the invoice in Guliel → Guliel produces the PDF and the Peppol BIS XML → your Access Point relays to the buyer and reports to IRAS where required.

Pricing in SGD context

Pricing is per organisation, not per seat — the same Free / $20 / $99 tiers across every country. The Free tier covers 200 invoices a month, which is more than enough for most SG sole proprietors and early-stage companies. The $20 Standard tier covers up to 5,000 invoices a month and unlocks unlimited automations — fine for most SMBs. Local-currency pricing is on the roadmap; today's pricing is USD.

Why bootstrapped-from-Singapore matters

We say it because it changes the product, not because it's a marketing line. The Singapore GST tax invoice was the first document type built, the IRAS field requirements drove the data model, and "GST registration number on every invoice" was a Day 1 constraint, not a future feature. No marketing department, no investors, no bureaucracy — that's the operating shape, and it's why country-specific compliance ships fast.

FAQ

Do I have to switch to InvoiceNow today?

No. If you're an existing GST-registered business issuing PDF tax invoices, you remain compliant under current IRAS guidance. The mandate phases in over 2025–2031, starting with new voluntary GST registrants. The direction of travel is clear, but the date that applies to you depends on your cohort.

Is Guliel a Peppol Access Point?

No. Guliel produces Singapore-compliant tax invoices and the Peppol BIS Billing 3.0 structured payload from the same source. Transmission to IRAS and trading partners over the Peppol network goes through an IMDA-approved Access Point provider. We integrate; we don't operate the network.

What's the GST rate Guliel applies by default?

9% — the standard rate in effect since January 2024. Reduced and zero-rated supplies are configurable per line item. Out-of-scope and exempt supplies are supported.

Can I issue a simplified tax invoice?

Yes, for transactions up to SGD 1,000 including GST, with the reduced field set IRAS allows. Guliel will produce the simplified format automatically when the total qualifies.

Does Guliel work for businesses outside Singapore?

Yes. We support 38+ countries today, with more shipping monthly. Singapore is the home market and the most complete implementation, but the same platform handles US Commercial Invoices, EU VAT invoices, XRechnung, ZUGFeRD, Japan QIS and others. See /invoicing for the full country list.

How does Guliel handle the API side for developers?

Full REST API plus an MCP server for AI-agent access. You can issue invoices, log expenses, query reports and trigger automations programmatically. See /product/api.

Start free at /pricing — Singapore-built, no card required.