A guide for the person who keeps the books
What InvoiceNow changes for your GST bookkeeping
Two separate things — a tax and a delivery network — decide what your invoices have to say and who can send them. This guide keeps them apart, then shows where they meet.
GST is not e-invoicing
Two requirements that get confused at the same desk
GST is a tax. IRAS administers it, it applies to your supplies and purchases once you are registered, and it exists whether your invoices are on paper, in a PDF or in a structured data format.
InvoiceNow is a delivery network — Singapore's Peppol-based e-invoicing network for sending and receiving structured e-invoices. It is an automation and compliance topic, not a tax in itself.
The confusion arises because a structured e-invoice carries the same GST information a compliant tax invoice does, in fields a machine can read. Getting the format right is a technology question. Getting the tax treatment right is an accounting one, and software will not decide it for you.
Keep the two apart in your head and the vendor conversations get much clearer. The next three sections answer GST first, InvoiceNow second, then the checklist for choosing software that handles both.
The tax question
What a GST-compliant tax invoice needs
IRAS specifies the information a tax invoice must show for GST purposes. Two minutes with this list is worth more than any demo, because software stores these as fields — an invoice template either contains the required elements or visibly does not.
There are also rules about when a simplified tax invoice can be used for smaller amounts. The full picture sits in the IRAS guidance for your circumstances; this page is the orientation, not the authority.
-
01
Your GST registration number
The number IRAS issued when you registered, shown on the invoice you send.
-
02
An identifying invoice number
Your own running series, unique to that invoice.
-
03
The date of the invoice
Distinct from the date the supply is treated as made, which affects the return it lands in.
-
04
Customer's name and address
Both — this is where a free-text template usually stops passing.
-
05
A description of the goods or services
Enough for the reader to know what was supplied.
-
06
Amount before GST, the rate applied, the GST amount, the total
Four numbers on four lines, each one carrying a distinct meaning.
What software cannot do is tell you whether a particular supply is standard-rated, zero-rated or exempt. That is a determination you or your accountant make — one of the reasons GST handling sits near the top of our evaluation criteria.
InvoiceNow, plainly
A channel, not a system
InvoiceNow transmits invoices as structured data over the Peppol network rather than as a PDF attached to an email. The invoice arrives in the recipient's system already parsed into fields, which is why the network reduces manual keying on both sides.
For a Singapore business, the practical significance is that e-invoicing readiness has become a software buying criterion rather than a future project. It appears alongside GST and IRAS workflows in almost every serious comparison now.
It is not a replacement for your accounting system. It is a channel your accounting system either supports directly or does not — and the difference between those two states is the subject of the next two sections.
Where to confirm readiness
Checking the IMDA InvoiceNow-ready list
IMDA maintains the authoritative list of InvoiceNow-ready solutions. That list — not a vendor's landing page and not a comparison article — is where readiness should be confirmed for a specific product and edition.
Readiness is version-specific and edition-specific. A platform can be ready in one market and not another, or ready in its current release and not in the one your accountant installed two years ago.
-
1
Open IMDA's own InvoiceNow-ready list and search for the product you are considering.
-
2
Match the exact edition, not the brand name — the plan tiers differ.
-
3
Confirm with the vendor in writing that the edition you are buying appears on that list.
What a vendor page shows
Intent to support
- Useful for scope — what the platform plans to cover
- Frequently ahead of a released edition
- Not the record of what has been confirmed
What IMDA's list shows
Confirmed readiness
- Tied to a specific product and edition
- The record to quote if a dispute comes up
- Where our directory checks its own entries
Our directory notes where a platform's readiness is stated by the vendor and where it is confirmed against the list. We would rather flag the difference than paper over it.
Two minutes with the list is worth the awkward conversation it prevents later.
The detail that catches people
Readiness is a capability, not a switch
A platform being InvoiceNow ready means it can send and receive on the network. It does not mean your business is registered, onboarded or configured to do so.
Proves — the platform
Sending and receiving on InvoiceNow
The software can speak Peppol. This is what the IMDA list confirms, edition by edition.
Does not prove — your business
Registered, onboarded and routed
Your entity is on the network, details confirmed, and an internal owner handles what arrives.
Registration and onboarding involve your accounting software provider or your accounting firm, and they involve steps outside the software: identifying yourself on the network, confirming your details, and establishing how incoming invoices will be routed and approved internally.
Plan for that as a project with an owner, not as a setting. The businesses that struggle are usually the ones that assumed readiness and activation were the same thing, then discovered a queue of inbound documents nobody had decided how to handle.
The daily difference
What changes in your bookkeeping
The daily difference is mostly at the edges. Less keying in, fewer transcription errors — same judgement in the middle.
- Outbound invoice leaves your desk
-
BeforeRecipient types it in, or a PDF gets filed as an attachment.
InvoiceNowLeaves as structured data; the recipient keys less.
- Inbound invoice arrives
-
BeforeSomeone retypes it, or drags the PDF into the ledger manually.
InvoiceNowArrives already parsed into fields, fewer typos.
- Deciding on the invoice
-
BeforeSomeone checks it, codes it, decides when it gets paid.
InvoiceNowExactly the same — an e-invoice does not approve itself.
- Reconciling the bank
-
BeforePayment matching sits in the reconciliation screen.
InvoiceNowAlso unchanged — that is why we assess bank feeds separately.
The gain is real but bounded: less manual entry at the edges, the same judgement in the middle.
Before you subscribe
Three questions to put to any vendor
Ask before you subscribe rather than after you have migrated your chart of accounts.
-
01
Does this edition send and receive on InvoiceNow?
And does the exact edition appear on the IMDA list? If the vendor cannot name the edition, treat that as the answer.
-
02
How is the GST treatment of an inbound invoice recorded?
And can it be reversed cleanly if the supplier amends the invoice later?
-
03
When a transmission fails, who do I contact?
The question most buyers forget, and the one that determines how a bad week feels.
If you are GST-registered, weigh GST handling first and InvoiceNow second. If you are not, and larger customers start asking for structured invoices, the order flips.
Questions we get asked
FAQ
Where your circumstances may differ from a summary, we say so and point at the authority instead of guessing.
Is InvoiceNow mandatory for my Singapore business?
Not in general terms, and we are not going to state a blanket obligation that may not apply to you. InvoiceNow is a voluntary network with adoption encouraged through government guidance, and obligations have been introduced in specific contexts over time. Check the current IMDA and IRAS guidance for your situation rather than relying on a summary, including this one.
Can I be GST-compliant without InvoiceNow?
Yes. GST compliance is about the tax treatment and the information on your tax invoice, not about the delivery format. A correctly prepared invoice sent as a PDF can satisfy the tax invoice requirements. InvoiceNow changes how the invoice travels, not what the tax law requires it to say.
Does my accounting software need InvoiceNow support to file GST?
No. GST filing and e-invoicing are separate. Software with strong GST handling can support your filing workflow without being an InvoiceNow channel, and a platform that is InvoiceNow ready can still be poor at the bookkeeping around a GST return. Assess both, but do not treat them as one requirement.
Where do I confirm a platform actually appears on the IMDA list?
Go to IMDA's own InvoiceNow-ready list and search for the product and edition you are buying. Vendor pages are useful for finding out what a platform intends to support, but the official list is the record of what has been confirmed.
Where to next
Start with the software list, or send us the question we have not answered
Our directory shows how each platform handles GST recording, IRAS-facing workflows and InvoiceNow readiness, with a note on where readiness is vendor-stated and where it is confirmed against IMDA's list.
This guide is orientation, not tax advice, and it does not replace the current IMDA and IRAS guidance for your own circumstances. LedgerLane is an independent editorial resource — questions and corrections go to the editorial team at contact.