InvoiceNow: what you send IRAS, per its September 2026 FAQ

Once IRAS’s GST InvoiceNow Requirement applies to a GST-registered business, it sends IRAS the data on the invoices and equivalent documents behind its GST return: standard-rated, zero-rated and exempt sales, and standard-rated and zero-rated purchases, credit notes included, apart from a short list of exclusions. A Peppol invoice sent to a customer on the InvoiceNow network is copied to IRAS automatically once the business’s submission feature is on. Other invoice data, such as PDF or paper sales invoices, point-of-sale takings and purchase invoices, is recorded in the business’s InvoiceNow-Ready software and sent to IRAS as a “solution-extracted” invoice.

The dates are in our plan-backwards guide and are not repeated here. This page reads IRAS’s FAQ for the requirement, the version dated 23 September 2026, and maps eight common situations to the answer that covers each. It is general information, not tax advice. The FAQ’s amendment table lists four amendments, the first dated 16 October 2025, so recheck it before you configure anything.

What does InvoiceNow send to IRAS, and what stays out?

InvoiceNow is Singapore’s nationwide e-invoicing network, based on the Peppol standard, with IMDA as Singapore’s Peppol Authority. The e-Tax Guide describes four routes by which IRAS gets data; each answer below depends on the route:

1. Type 1A: a Peppol invoice you send to a customer on the network. IRAS’s copy is automatic.
2. Type 1B: the recipient’s own record of that Peppol invoice, to which it adds the GST category code and the input tax it will claim. If you buy from a supplier on the network, this is your purchase data.
3. Type 2: a sale made outside the network, such as a PDF or paper invoice or a sale to a customer not on InvoiceNow.
4. Type 3: a purchase made outside the network, such as a PDF supplier invoice or a petty cash purchase.

Types 1B, 2 and 3 are extracted from your software regularly, for example daily or weekly, but each must arrive by the deadline above. The rule is to send what is reported in your GST return, minus exclusions. According to the e-Tax Guide and the requirement page, these stay out:

• Documents that are not bills for payment: sales orders, pro-forma invoices and statements of account.
• Deemed supplies such as free goods, goods exported without actual sales, and reverse charge supplies and purchases.
• Exempt financial services, exchange or loan of digital payment tokens, and import permits.
• Out-of-scope supplies, and non-reportable purchases: from suppliers who are not GST-registered, with input tax blocked (the guide’s example is motor car expenses), or exempt.
• Pre-registration GST claims and bad debt relief claims (FAQ 2.2).

Two details are easy to miss. If an invoice or credit note has even one line inside the requirement, the whole document is sent. And with no invoice there can still be data: when related entities offset receivables and payables, the supply data goes when the transaction is posted (FAQ 2.3).

What goes to IRAS in eight common situations?

Each line says what IRAS receives and cites the IRAS FAQ question that answers it (“FAQ 3.12” is question 3.12).

1. A Peppol invoice to a customer on InvoiceNow. IRAS gets a copy automatically, generally in real time or near real time, if the GST InvoiceNow submission feature is activated. The copy goes even if the customer later rejects the invoice. The fix is a credit note or, if the money value is unchanged, a revised invoice reusing the original Document UUID. FAQ 1.4, 3.1, 3.17, 5.4, 5.5.
2. An invoice to a customer not on the network. Record it in your InvoiceNow-Ready Solution and it goes as a solution-extracted invoice; Access Point providers cannot convert PDF or paper invoices to Peppol. It is sent whether or not the customer is GST-registered or claims input tax. You still collect the customer’s name, UEN and address, as missing mandatory fields are rejected, though “NA” may be entered for non-GST-registered individuals. FAQ 3.2, 3.14, 3.21, 4.1, 4.5.
3. Restaurant or shop POS receipts. You may keep issuing receipts rather than Peppol invoices, but the sales data must still reach IRAS, and may be recorded in aggregated form with customer fields defaulted to “POS”. Only POS sales, simplified tax invoices (which include serially numbered receipts) and petty cash purchases may be aggregated. FAQ 3.4, 3.12, and e-Tax Guide 7.8 to 7.10.
4. Purchase invoices where you claim input tax. Standard-rated and zero-rated purchases are sent, and your record adds the input tax you claim, so it can differ from your supplier’s sales data. FAQ 2.1.
5. Purchase invoices where you do not claim input tax. From a GST-registered supplier these fall outside the requirement, though you may send them with category code “OP”. Partially exempt businesses that fail the de minimis rule follow a different rule: e-Tax Guide 12.10 to 12.12 has them submit all purchase invoice data with GST incurred, except disallowed expenses, whether or not input tax is claimed. FAQ 2.7, and e-Tax Guide 7.3 and 12.11.
6. Credit notes and volume rebates. A credit note is sent even when the GST amount is unchanged, with the original invoice’s category code, such as “SR”. For a volume rebate, give the original invoice numbers and dates, or leave them blank if it cannot be tied to particular invoices. Cancellation documents can go as credit notes if they capture the details a credit note requires, and debit notes go as solution-extracted invoices, not through the network. FAQ 3.3, 3.10, 5.3, 6.1.
7. Duplicate PDF copies. Whether to send a PDF or paper copy after a Peppol invoice is a business decision; IRAS says it should be marked as a duplicate copy, and the customer should make sure it does not claim input tax twice. FAQ 3.11.
8. GST group registration. A group still files one consolidated GST return, but its entities may send invoice data separately or on a consolidated basis through the representative. A new voluntary registrant joining a group follows the group’s phase, yet the e-Tax Guide says implementation dates for all members of new and existing groups and divisions “will be communicated at a later date” (12.5). FAQ 7.1, 7.2.

How does this look for a restaurant and a trading firm?

Both examples are fictional: the businesses, figures and exchange rate are invented, and GST is shown at 9%, the rate IRAS’s e-Tax Guide uses in its examples, for instance S$630 on S$7,000 in Example 9.

A neighbourhood restaurant, one trading day.

• Dining and takeaway: 212 POS receipts totalling S$9,000 plus S$810 GST. Customers still get receipts, and the owner records the day as one aggregated entry (customer fields “POS”, code “SR”).
• A company’s catering order, S$1,500 plus S$135 GST: a Peppol invoice, because the customer is on InvoiceNow.
• Gas cylinders, S$400 plus S$36 GST on a supplier’s PDF: a Type 3 purchase if the input tax is claimed.
• Vegetables, S$250 cash from a stall that is not GST-registered: not sent.

On those assumptions, three records reach IRAS that day, covering S$9,000, S$1,500 and S$400 before GST.

A small trading firm, one quarter.

• Customers: 30 business customers, 6 on InvoiceNow. Six get Peppol invoices (Type 1A) and 24 get recorded PDF invoices (Type 2); all 30 go to IRAS.
• Export sale: US$10,000, zero-rated, code “ZR”. At an invented rate of 1.30 that is S$13,000; in practice the firm must convert at the exchange rates IRAS approves for GST (FAQ 6.2).
• Rebate: a credit note of S$2,000 plus S$180 GST. The data is sent even if the parties choose not to adjust the GST, which IRAS allows only if both choose it and meet the conditions (e-Tax Guide 11.2, 11.3; FAQ 5.3).

What should you ask your software provider?

IRAS says solutions present submission information differently (FAQ 3.9), so ask rather than assume. These questions are our suggestion, not an IRAS checklist; email them and file the replies.

1. Is the product on IMDA’s accredited InvoiceNow-Ready Solutions list, and does my plan include the GST InvoiceNow submission feature? (FAQ 1.4, 1.9)
2. Does it extract PDF and paper sales and supplier bills, and how often, against my filing deadline? (FAQ 3.1, 3.17)
3. Can it aggregate POS sales and petty cash, and will my POS connect to it? (FAQ 3.4, 3.12)
4. For partly claimed purchases, does it send the claimable portion or the whole invoice, consistently? (e-Tax Guide 7.5 to 7.6)
5. How does it handle credit notes, rebates, cancellation documents and debit notes? (FAQ 3.3, 3.10, 5.3, 6.1)
6. If I edit a sent invoice, does it resubmit with the original Document UUID? (FAQ 5.1, 5.4; e-Tax Guide 11.10, 11.13)
7. Can I see what was submitted, its status and IRAS’s acknowledgement IDs, to reconcile with my return? (FAQ 3.9, 3.20, 9.1)

Can you opt out, and will a mismatch bring a penalty?

There is no opt-out. Only Excluded Businesses, meaning overseas entities and businesses registered for GST wholly because of the reverse charge regime, are outside the requirement, and IRAS says small, low-volume, related-party-only and wholly zero-rated or exempt businesses cannot ask for exemption (FAQ 2.6, 9.2). IRAS says it will calibrate enforcement during the initial phases of onboarding for genuine mistakes in invoice data that are not due to negligence or made without reasonable excuse, but that enforcement action may be taken against non-compliant businesses. A business that registers voluntarily from 1 November 2025 may have its GST application refused or its registration revoked if it does not comply (FAQ 9.2). None of the three pages read here states a penalty amount. The e-Tax Guide (9 March 2026) also says legislation for all remaining registrants “will be enacted at a later date” (2.3(b)). These pages do not say whether it has been, so check before relying on a date.

IRAS expects invoice data to tally with your GST return but recognises legitimate differences, such as timing and input tax not claimed in full, and says businesses will not be penalised so long as they adhere to the record keeping requirements and can produce the records on request (FAQ 9.1). Those include keeping records, with source documents, for at least five years (FAQ 9.3; see our guide to how long to keep business records). When you join depends on how and when you registered: our plan-backwards guide sets out the phases and our GST registration guide covers when registration is compulsory.

What changed on 23 September 2026, and what should you recheck?

The latest FAQ version added questions 1.2 (why the rollout is phased) and 1.14 (a franchise group on a shared ERP may ask IRAS to extend its mandatory date). It amended question and answer 5.1, and answers 1.7, 1.8, 5.2 and 6.4. IRAS lists what changed but not how, so compare with any copy you saved.

Two of the amended answers affect daily processing. Under 5.1, an amended invoice record, for example a category code changed from TX to OP, is resubmitted and IRAS treats the last submission as the latest. Under 5.2, if input tax attribution cannot be settled when you submit a purchase, you submit on your assessment then and are not expected to adjust later where the invoice value has not changed. Our inference is that 5.1 covers an edited record and 5.2 a later claim decision; ask IRAS or your provider about period-end reclassifications.

Recheck by 31 October 2026, and again before you sign with a provider:

1. Confirm the FAQ still says “Version: 23 Sep 2026”, as it did on 17 October; if it is newer, read its amendment table first.
2. Look for IRAS’s list of free-of-charge packages for 1 April 2027 to 31 March 2031, and ask your provider whether its package will be on it.
3. Match your provider’s replies to the FAQ numbers above, and save a dated copy of the FAQ you relied on.

More on running a GST-registered business is in our operations guides, and our GST worked examples show GST on a quote or invoice.

Common questions