Invoicing Software for Singapore
A short checklist for Singapore businesses comparing invoicing tools, built on IRAS's own wording, followed by what Billed's pages say it does.
Before comparing tools, list what each invoice must hold. IRAS's "Invoicing customers" page (Singapore, last updated 30 October 2026) says "All required information must be clearly stated on a single document." Its list for a tax invoice runs from "Description of goods/services supplied" to "Total amount payable including GST". A tool is only worth trying if it lets you put every one of those items on one invoice.
Timing matters as well: the same IRAS page says a tax invoice is issued "Within 30 days from the time of supply". Whether you have to register for GST in the first place is a question for IRAS's registration pages or a local accountant, and the Singapore invoicing guide covers the rules in more depth.
Worked example in Singapore dollars, with sample figures: a GST-registered consultancy bills a GST-registered client $1,200.00 for a standard-rated service. IRAS's rates page (Singapore, last updated 13 June 2025) says "The current GST rate in Singapore is 9%." At that rate the GST is 9% of $1,200.00 = $108.00, bringing the invoice to $1,308.00. Check the rate and treatment of your own supply with IRAS.
Invoicing rules in Singapore
Local rules change over time; use these themes as a checklist and confirm details with a qualified adviser for your situation.
Everything on one document
IRAS (Singapore, last updated 30 October 2026): "All required information must be clearly stated on a single document." It adds: "Missing or incomplete information may result in your customer being unable to claim input tax." Make sure every required item fits on the invoice a tool produces.
Issued on time
IRAS (Singapore, last updated 30 October 2026) sets the timing: "Within 30 days from the time of supply". Make sure you can date an invoice and send it the day the job ends.
Zero-rated sales shown clearly
IRAS (Singapore, last updated 30 October 2026): "If you issue a tax invoice for zero-rated supplies, state on the invoice that GST is charged at 0%." Make sure you can show a 0% line where it applies.
The rate on each invoice
IRAS lists "GST Rate" among the required information (Singapore, last updated 30 October 2026), and its rates page (last updated 13 June 2025) says "The current GST rate in Singapore is 9%." Make sure you can set the rate on an invoice yourself.
Billed features
Convert An Estimate To Invoice
Billed's invoice software page says you can "convert an approved estimate into an invoice".
Frequently Asked Questions
Invoicing Software in Other Countries
Start Invoicing With Billed
Create invoices, track payments and keep your clients' details in one place with Billed.
At a glance
| What to check | IRAS source (Singapore) |
|---|---|
| Every required item on one document | "Invoicing customers", last updated 30 October 2026 |
| Issued on time | The same page |
| Zero-rated sales | The same page |
| The rate | "Current GST rates", last updated 13 June 2025 |
When this isn't for you
If the way you invoice clients today already works for you, there's no need to switch.