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Answers · GST · InvoiceNow · phases 1 and 2 in force, phase 3 announced for 1 Apr 2028

InvoiceNow: who is mandated, from when, and what should a company do if it is not?

Today the GST InvoiceNow Requirement binds two groups: a newly incorporated company that registers for GST voluntarily within 6 months of incorporation, since 1 Nov 2025, and every new voluntary GST registrant, as a condition of registering, since 1 Apr 2026. The rest is announced policy that IRAS says will be legislated later: from 1 Apr 2028 every new compulsory GST registrant, and every existing GST-registered business by its total annual supplies, in four phases from 1 Apr 2028 to 1 Apr 2031.

A company that is not GST-registered is in no phase at all. A GST-registered company that is not mandated yet has nothing to send, and the sensible work now is to know its phase and get its invoice data right, because the format is settled and the rules on it have already tightened.

Phases and dates from the rulebook, the rest checked by hand Edition YA-2027 · sources verified through 24 Jul 2026

The phases

Invoice data goes to IRAS automatically, through the Peppol network, instead of being typed into a return. It is arriving in phases. Two phases are in force; the four that follow are dated 1 April of each year from 2028 and are shown as announced because the GST Act amendments behind them had not been passed when IRAS last revised its guide.

PhaseFromWhoStatus
11 Nov 2025A newly incorporated company that registers for GST voluntarily within 6 months of incorporationin force
21 Apr 2026Every new voluntary GST registrant, as a condition of the registrationin force
31 Apr 2028Every new compulsory GST registrant, and every existing GST-registered business with total annual supplies of S$200,000 or lessannounced
41 Apr 2029Existing GST-registered businesses with total annual supplies of more than S$200,000, up to S$1,000,000announced
51 Apr 2030Existing GST-registered businesses with total annual supplies of more than S$1,000,000, up to S$4,000,000announced
61 Apr 2031Every remaining GST-registered business, with total annual supplies of more than S$4,000,000announced

Total annual supplies means box 4 of the GST return, standard-rated, zero-rated and exempt supplies together, added up across the prescribed accounting periods that ended in calendar year 2025. It is a fixed measuring year, not one that moves with you. A business without a full year of periods ending in 2025 scales its figure to a 365-day equivalent. See what goes in box 4.

Left out of the requirement altogether: an overseas business that has to appoint a local section 33(1) agent, an overseas vendor registered under the Overseas Vendor Registration regime, and a business that is GST-registered only because of the reverse charge on imported services or low-value goods. A foreign company's Singapore branch is not overseas for this purpose and stays in.

Find your phase

Worked

Three existing GST-registered companies, one measuring year

Each company adds up box 4 across its GST returns for the periods ending in 2025 and reads its phase off the thresholds above.

CompanyBox 4 across 2025BandPhase
Company Aa small consultancy, registered voluntarilyS$150,000S$200,000 or lessPhase 3, from 1 Apr 2028
Company Ba trading company, registered voluntarily below the compulsory thresholdS$650,000more than S$200,000, up to S$1,000,000Phase 4, from 1 Apr 2029
Company Ca wholesaler, well over the compulsory thresholdS$5,200,000more than S$4,000,000Phase 6, from 1 Apr 2031

Company A is in the first banded phase because its supplies are S$200,000 or less. Company B's supplies of S$650,000 are more than S$200,000, up to S$1,000,000, so it waits a year longer. Company C is above every threshold and comes in with the last phase. All three dates are announced, not enacted, and IRAS's own page is the thing to re-read before building a plan on them.

A company that registers for GST from now on does not use this table. A voluntary registrant is bound from the day it registers, since 1 Apr 2026. A company that registers compulsorily on or after 1 Apr 2028 is due to come in as a new compulsory registrant under the announced phase 3. A company that registers compulsorily between now and 1 Apr 2028 is not bound today, and the sources on file do not say which phase it falls in afterwards: they name new compulsory registrants from 1 Apr 2028 and existing businesses by their 2025 supplies, and nothing on file places a business that is neither. This page does not guess; ask IRAS before building a plan on a date.

What the requirement asks of a mandated business

InvoiceNow is Singapore's Peppol network, run by IMDA as the Peppol Authority. An e-invoice leaves your software, goes through your Access Point to your customer's Access Point, and lands in their software. The GST requirement adds IRAS as a fifth corner: every invoice sent over the network is copied to IRAS automatically, and invoice and purchase data that did not travel over the network (a purchase from a supplier who is not on it, a sale that did not go through it) is extracted from your software and submitted to IRAS by API.

The data for a GST period is due at IRAS by the earlier of the day you file that period's GST return and the return's due date. Network invoices arrive as you send them; the extracted data you submit regularly, daily or weekly in IRAS's examples.

To do any of it you need one of two things: an InvoiceNow-Ready solution, which is accounting software IMDA has accredited to send, receive and submit, or, for a company running its own system, a connection to an accredited Access Point. IRAS suggests three to twelve months for an in-house system to be connected.

If you are not mandated yet

Nothing is due from you, and nothing is sent. Four things are worth doing anyway, in this order.

  1. Know your phase. If you are GST-registered, add up box 4 across your 2025 periods and read the table. If you are not registered, the requirement does not reach you until you register, and a voluntary registration now brings it with it as a condition.
  2. Get the invoice data right. The format is PINT-SG, and the release in force since 7 Sep 2026 rejects an invoice that carries no customer reference or purchase order number, or no street address and postal code for either party. Collect your customers' UENs, their addresses and postal codes, and a reference from each of them once, and every invoice after that is clean whether or not it ever travels over the network.
  3. Decide whether to join early. The network is open to any business already, mandated or not, and a customer who is on it may ask for e-invoices before any phase reaches you. The free-of-charge package IMDA lists runs until 31 Mar 2027. The S$1,000 transition grant is open from 1 Jul 2026 to 31 Mar 2030 to a business with total annual supplies of S$4,000,000 or less, towards a paid subscription of at least 12 months or an Access Point connection, and only to a business that is not already subscribed or connected. Neither is a reason to join before you are ready. Read the grant's conditions before signing with a provider, because a business that has already connected is outside it.
  4. Keep the books that the data will come from. The data IRAS receives is your invoices and purchases, period by period. Books that already tie every invoice to a posted entry and every GST box to its documents are the starting point; the connection is the last step, not the first.

The format: PINT-SG, and what changed on 7 Sep 2026

The invoice that travels over InvoiceNow is an XML document in the PINT-SG specification, Singapore's version of the Peppol international invoice, in UBL 2.1. The release in force today is PINT-SG 1.4.1, which took over from 1.4.0 on 7 Sep 2026.

The change matters to a small company more than the version number suggests. 1.4.1 makes seven rules fatal that were only warnings under 1.4.0, and adds new fatal rules beside them. Three reach an ordinary invoice: it must carry the customer's own reference or their purchase order number (a new rule), and both the supplier's and the customer's street address and postal code (BR-106 and BR-107, warnings until this release). An invoice missing any of them is rejected by the receiving Access Point rather than delivered. The other promoted rules cover each party's registered company identifier, the invoice's own unique identifier and the tax currency code. The new fatal rules the rulebook names, BR-50-SG and BR-CO-25-SG, ask for a payment account identifier when the invoice offers a credit transfer, and a due date or payment terms when an amount is due. Those are facts about you, your customers and how you get paid, not about tax, and they are cheap to collect once.

Do it in Simpler Tax

An invoice issued here comes with its PINT-SG twin

Issue an invoice in Simpler Tax and it writes the paper copy and the PINT-SG XML from one set of figures, and posts the sale and the receivable from the same figures again. The XML needs the customer's UEN; without one the paper invoice and the books are unaffected and only the XML twin is withheld, with the reason. The issue screen reads the rulebook for the release in force: an invoice missing the customer's reference, or a street address and postal code, is named on the spot, with the day the rule started to bite and what to add before issuing it again. Peppol XML you receive goes in as a document, like a PDF. Simpler Tax sends nothing over the network; the XML is a file for you or your Access Point to send.

Download for Windows Simpler-Tax_1.0.0_x64-setup.exe · 55 MB · not signed yet · free · SHA-256 on the home page

Questions people ask

I am not GST-registered. Does InvoiceNow apply to me?

No. The GST InvoiceNow Requirement is a requirement on GST-registered businesses. A company whose taxable turnover has not gone over the S$1,000,000 registration threshold and has not registered voluntarily is outside every phase. It becomes relevant the day you register: a voluntary registration since 1 Apr 2026 carries the requirement as a condition, and a compulsory one on or after 1 Apr 2028 would too if that phase is enacted as announced. For a compulsory registration between now and 1 Apr 2028 the sources on file name no phase, and this page does not guess one.

My company registered for GST voluntarily before 1 Nov 2025. Which phase am I in?

You are an existing GST-registered business, so your phase follows your total annual supplies: box 4 of your GST returns added up across the accounting periods that ended in 2025. S$200,000 or less puts you in phase 3, from 1 Apr 2028; more than S$200,000, up to S$1,000,000 in phase 4, from 1 Apr 2029; more than S$1,000,000, up to S$4,000,000 in phase 5, from 1 Apr 2030; above that, phase 6, from 1 Apr 2031. Those four phases are announced policy, not yet law.

Which year decides my band, and does it move?

Calendar year 2025, and it does not move. IRAS measures total annual supplies over the prescribed accounting periods ending in 2025, and a business without a full year of periods in 2025 scales the figure to a 365-day equivalent. Growth after 2025 does not push you into an earlier phase, and a quiet year after it does not push you into a later one.

Are the 2028 to 2031 dates law?

Not yet. Phases 1 and 2 are in force. The 2028 to 2031 phases were announced at the Committee of Supply in 2026, and IRAS's e-Tax Guide says the GST Act amendments for them will be enacted later. The rulebook carries them as announced, and this page prints them that way; it is rebuilt after each check of the IRAS page.

Is there a free way to comply?

Yes, for now. IMDA lists a free-of-charge InvoiceNow solution package, a set of accredited providers offering e-invoicing and GST InvoiceNow submission at no charge to GST-registered businesses, available until 31 Mar 2027. A second package for the period after that has been announced with no published details. Separately, a GST InvoiceNow transition grant of S$1,000 is open to a GST-registered business with total annual supplies of S$4,000,000 or less over 2025, from 1 Jul 2026 to 31 Mar 2030 or until the funds are claimed. It defrays a paid subscription of at least 12 months to an accredited solution, or a connection through an accredited Access Point, and it is not open to a business already subscribed to an accredited solution or already connected to InvoiceNow. IMDA's grants page, in the sources, carries the conditions.

Does Simpler Tax send my invoices to IRAS or to my customers?

No. Simpler Tax writes the PINT-SG XML file beside the paper invoice, from the same figures, and leaves both on your disk. It sends nothing over the network, to IRAS or anyone. Transmitting an e-invoice, and the copy IRAS receives, is the job of an accredited Access Point or InvoiceNow-Ready solution; Simpler Tax is neither, claims no accreditation from IMDA and no endorsement from any authority.

What happens if a mandated company does not comply?

Not settled for the early phases. For a voluntary registrant the requirement is a condition of the registration, and IRAS's guide says a registrant that does not comply risks having the GST registration revoked.

Sources

Statutory figures on this page are read from the Simpler Tax rulebook at build time, edition YA-2027, every source last checked 24 Jul 2026. The rulebook entries named below are the ones this page was computed from; the IRAS pages are what they were verified against.