Since 1 April 2026, every new voluntary GST registrant in Singapore has been required to issue invoices through InvoiceNow-ready software, a Peppol-based e-invoicing standard (specifically the BIS Billing 3.0 format) that sends structured invoice data directly between accounting systems, rather than as a PDF or paper document. Mandatory GST registrants are being brought into the same requirement in phases over the following years.
Why This Isn’t Just a Formatting Change
The easy way to think about InvoiceNow is “invoices, but digital.” That undersells what’s actually changing. Instead of emailing a PDF invoice that someone on the other end has to manually re-enter into their own accounting system, InvoiceNow transmits structured data directly between systems, the recipient’s software receives the invoice already in a format it can process, with no manual re-entry and far less room for transcription error on either side.
What You Actually Need
Accounting software that’s InvoiceNow-ready, most major cloud platforms used in Singapore, including Xero and QuickBooks, support this through registered Peppol access points, though the exact setup varies by provider. If you’re already on a modern cloud accounting platform, this is often a configuration step rather than a full system change. If you’re still on older desktop software or manual invoicing, this is one more reason a move to cloud accounting is worth timing deliberately rather than putting off.
If You’re a New Voluntary Registrant Right Now
This requirement already applies to you, it’s not a future consideration. If you’re registering for GST voluntarily and haven’t set up InvoiceNow-compliant invoicing yet, this needs to be part of your registration process now, not an afterthought handled after you’re already issuing invoices the old way.
If You’re an Existing Registrant
The mandatory phase-in affects existing registrants on a staggered timeline based on registrant category, rather than all at once. Worth checking where your specific registration status falls in that timeline rather than assuming you have the same runway as a business in a different category.
Where This Fits With Everything Else
Getting InvoiceNow set up properly usually happens alongside either GST registration for new registrants, or cloud accounting setup for existing registrants moving off older systems. It’s rarely worth treating as an isolated task separate from whichever of those two situations actually applies to you.