Singapore Invoice Requirements

Overview

Singapore's invoice requirements are governed by the Inland Revenue Authority of Singapore (IRAS) and include specific rules for GST tax invoices, simplified invoices, e-invoicing compliance, and record-keeping. Businesses must adhere to these regulations to ensure proper GST reporting and input tax claims.

GST Tax Invoice Requirements

Mandatory Elements

A standard GST tax invoice must include:

The words "Tax Invoice"
Supplier's name, address, and GST registration number
Customer's name and address
Invoice date and unique identifying number
Description of goods/services
Total amount payable excluding GST
GST rate and total GST amount
Total amount payable including GST

When to Issue

Required for sales to GST-registered customers
Must be issued within 30 days from the time of supply
Not required for zero-rated supplies, exempt supplies, deemed supplies, or sales to non-GST registered customers

GST Calculation Methods

Businesses may choose one of two methods for calculating GST:

Apply 9% GST to each item's value (excluding GST) and sum the amounts
Apply 9% GST to the total value of all items (excluding GST)

Rounding Rules:

Total GST can be rounded to the nearest cent
Cash payments can be rounded to the nearest 5 cents (business's choice)

Simplified Tax Invoices

For transactions not exceeding $1,000 (including GST), businesses may issue simplified tax invoices containing:

Supplier's name, address, and GST registration number
Invoice date and identifying number
Description of goods/services
Total amount payable including GST
Statement indicating "price payable includes GST"

E-Invoicing Requirements (InvoiceNow)

Singapore is implementing a nationwide e-invoicing framework called InvoiceNow, based on the PEPPOL standard. Key requirements include:

Phased Implementation

May 1, 2025: Voluntary early adoption begins
November 1, 2025: Mandatory for newly incorporated companies registering for GST voluntarily within 6 months of incorporation
April 1, 2026: Mandatory for all new voluntary GST registrants

Technical Requirements

Must use InvoiceNow-Ready Solutions
Must transmit invoice data to IRAS via the InvoiceNow network
Format requirements: Singapore PEPPOL PINT (exclusive format from 2025)
Must register in the SG Peppol Directory to obtain a Peppol ID

Data Transmission

Real-time reporting for "PEPPOL e-invoices"
Weekly submission recommended for "solution extracted invoices"
Due date: Earlier of GST return filing date or return due date

Credit and Debit Notes

Credit Notes

Must include:

Identifying number and date of issue
Supplier and customer details
Reason for credit and description of goods/services
Quantity, amount credited, and GST adjustments
Original invoice number and date

Debit Notes

Only appropriate for transactions with no GST charged (e.g., internal billings)
Must show same details as credit notes when used for supplier credits

Record Keeping

All invoices (issued and received) must be retained for at least 5 years
Records must be available for IRAS audit
No need to submit invoices with GST returns, but they serve as supporting documents

Compliance Considerations

Exemptions

Overseas entities and businesses liable solely due to Reverse Charge regime are currently exempt
Plans exist to extend requirements to all GST registrants in the future

Penalties and Errors

Businesses remain responsible for accurate GST reporting
Voluntary disclosure of errors may qualify for penalty reductions
Data security measures must be implemented for transmitted invoice data