The Essential Guide: Getting Your GST Invoicing Right for Your Business

Sep 29, 2025

3 min read

For any GST-registered business in Singapore, invoicing isn't just an administrative chore—it's a fundamental part of tax compliance. The Inland Revenue Authority of Singapore (IRAS) regularly reminds businesses that issuing the correct billing documents is crucial, especially since these invoices are the primary documents your GST-registered customers rely on to claim their input tax.

Failing to comply with the invoicing rules can be an expensive mistake, potentially leading to penalties of up to $5,000. Beyond the fine, poor invoicing can harm a company's reputation and create friction with customers.

Here is what SMEs need to know about issuing the right document every time.

What Type of Invoice Should Your Business Issue?

GST-registered businesses primarily deal with three types of documents: the Tax Invoice, the Simplified Tax Invoice, and the Receipt. The correct document depends on your customer’s GST status and the transaction value.

Document Type	When to Issue	Key Use for Customer
Tax Invoice	For supplies to GST-registered customers.	Supports their claim for input tax (GST paid on purchases).
Simplified Tax Invoice	For supplies to GST-registered customers where the total payment (including GST) is $1,000 or less.	Supports their claim for input tax (GST paid on purchases).
Receipt	Primarily for supplies to non-GST registered customers.	An acknowledgement of payment.

Key Information Required on Billing Documents

A valid invoice or receipt must contain specific information. Errors here are a common cause of non-compliance. Companies should check their templates against the following core requirements:

Required Information	Tax Invoice	Simplified Tax Invoice	Receipt
The words "Tax Invoice"	✓	×	×
Supplier's name and GST Registration Number	✓	✓	✓
Supplier's address	✓	✓	×
Customer's name & address	✓	×	×
Date of issue	✓	✓	✓
Identifying Number (e.g., invoice number)	✓	✓	× (must be serially printed)
Description of goods or services	✓	✓	×
GST Rate	✓	×	×
Total amount payable excluding GST	✓	×	×
Total amount of GST	✓	×	×
Total amount payable including GST	✓	✓	✓

For a Tax Invoice, a business must also include the customer’s name and address, the GST rate, the total amount excluding GST, and the total amount of GST charged.

Pro-Tip for Simplicity: Many businesses choose to issue a full Tax Invoice for all sales, regardless of the customer’s GST status or the transaction value. This ensures compliance is consistently met and simplifies their internal document management system.

Invoicing Health Check: What Your Business Must Do Today

To safeguard against penalties and maintain customer trust, every GST-registered business should perform a health check on its invoicing procedures:

Review and Update Templates: Review all existing invoice and receipt templates to ensure they contain every piece of required information for GST purposes.
Rectify Errors: If any non-compliant invoicing formats are discovered, promptly implement the necessary changes.
Reissue Corrected Invoices: If a GST-registered customer identifies an error on an invoice they need for their input tax claim, the business should promptly reissue a corrected, compliant invoice.

IRAS is constantly engaging with businesses to deepen their knowledge of GST rules. Companies are encouraged to take advantage of available resources, such as the IRAS video on practical invoicing tips, to ensure full compliance.

Need Help With Your GST Invoicing Compliance?

Navigating the nuances of GST invoicing can be complex for a busy SME. If your business needs assistance with reviewing your invoicing templates, ensuring compliance, or implementing new invoicing systems, contact us today. Our team can help you perform an invoicing health check and implement processes to avoid costly penalties and administrative hassle.

Disclaimer: This blog post provides general information on GST invoicing guidelines for educational purposes and is based on guidance provided by the Inland Revenue Authority of Singapore (IRAS). It does not constitute tax advice. Businesses should always refer to the official IRAS e-Tax guides and resources or consult with a qualified tax professional to ensure full compliance with current GST laws and regulations.