How many days do I have to issue a tax invoice in Singapore?

30 days from the time of supply, unless the Comptroller allows longer.

Does a customer have to ask for a tax invoice in Australia?

The 28-day duty runs from the customer's request. Sales worth A$75 or less before GST are outside it.

Do I need to send a tax invoice to every customer in Singapore?

A tax invoice is required for GST-registered customers. Customers who are not registered can be given a receipt instead.

What is the deadline in New Zealand?

28 days from the buyer's request, or a date you agree, for supplies over NZ$200 to a GST-registered buyer.

When must I issue a qualified invoice in Japan?

When a customer that is a taxable business asks for one. See Simplified tax invoices for who may issue the short form.

Can I back-date an invoice?

easySales lets you date an invoice earlier than today when you issue it, and warns when the number would then be out of date order.

When to issue an invoice

Copy for AI

Tax law sets when a GST-registered business must give its customer a tax invoice. In some countries the clock starts at the sale, in others when the customer asks. This page sets out the deadlines. It is general information, not tax or legal advice: check the sources at the end or ask your accountant before you rely on it.

In short

Country	Deadline	Applies to
Singapore	Within 30 days of the time of supply	Standard-rated sales to GST-registered customers
Australia	Within 28 days of the customer’s request	Taxable sales worth more than A$75 before GST
New Zealand	Within 28 days of the buyer’s request, or a date you agree	Sales over NZ$200 to GST-registered buyers
Japan	When a taxable business customer asks	Registered qualified invoice issuers
Malaysia	No fixed number of days found	Every sale of taxable services

Invoicing promptly also starts your payment terms sooner and keeps your tax return in step with your sales.

Country by country

Singapore

A tax invoice must be provided within 30 days after the time of supply, or within a longer period the Comptroller allows. The time of supply is the earlier of the invoice or the payment, so when the customer pays first, the 30 days run from the date you receive the payment. A tax invoice is not needed for zero-rated or exempt supplies, or for customers who are not GST-registered.

Hong Kong

There is no sales tax and no statutory deadline for invoicing. Agree invoicing and payment terms with your customer.

Australia

You must give a tax invoice within 28 days after the customer asks for one, unless the customer issues a recipient-created tax invoice. The duty does not apply to a sale whose value is A$75 or less, excluding GST.

New Zealand

Taxable supply information must be provided to a GST-registered buyer within 28 days of a request, or by another date you both agree, for supplies over NZ$200. Provide it once; if the buyer loses it, a copy does not need to be marked as a copy.

Japan

A registered qualified invoice issuer must give a qualified invoice when a customer that is a taxable business asks for one, and keep a copy. It may be given electronically. The duty does not arise when you make only exempt, non-taxable or out-of-scope sales. No fixed number of days was found in the official guidance.

Malaysia and Brunei

A business registered for service tax must issue an invoice for each taxable service, in Malay or English. No fixed deadline in days was found in the Act or the regulations. Brunei has no GST or VAT.

In easySales

Issuing a draft gives it its invoice number and today’s date; you can date it earlier, never later. See Issue an invoice.
A recurring invoice raises a draft for each period on schedule, ready for someone to check and issue, so regular charges go out on time. See Recurring invoices.
Money recorded as a Prepayment gets a deposit tax invoice on the day it arrives, where your tax settings make tax due on receipt. See Deposits and prepayments.

Examples

Lim & Co, GST-registered in Singapore, finishes a renovation for Harbour Café, a GST-registered customer, on 5 August and has not been paid. The time of supply is fixed by the invoice or a payment, whichever comes first, so Mei Tan issues the tax invoice the same week. Had the café paid SGD 3,270.00 on 1 August, before any invoice, the tax invoice for that payment would have been due by 31 August.

Common questions

How many days do I have to issue a tax invoice in Singapore? 30 days from the time of supply, unless the Comptroller allows longer.
Does a customer have to ask for a tax invoice in Australia? The 28-day duty runs from the customer’s request. Sales worth A$75 or less before GST are outside it.
Do I need to send a tax invoice to every customer in Singapore? A tax invoice is required for GST-registered customers. Customers who are not registered can be given a receipt instead.
What is the deadline in New Zealand? 28 days from the buyer’s request, or a date you agree, for supplies over NZ$200 to a GST-registered buyer.
When must I issue a qualified invoice in Japan? When a customer that is a taxable business asks for one. See Simplified tax invoices for who may issue the short form.
Can I back-date an invoice? easySales lets you date an invoice earlier than today when you issue it, and warns when the number would then be out of date order.

Sources

Last checked: 21 October 2026.

Singapore Statutes Online — GST (General) Regulations, regulation 10
IRAS — Invoicing customers
IRAS — GST: Time of Supply Rules (e-Tax Guide, PDF), paragraph 5.5
Federal Register of Legislation — GST Act 1999, sections 29-70 and 29-80
Inland Revenue NZ — How taxable supply information works
National Tax Agency Japan — Qualified invoice Q&A (PDF, Japanese), question 23
National Tax Agency Japan — Tax Answer No. 6498 (Japanese)
RMCD MySST — Service Tax Act 2018 (PDF), section 21