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Singapore InvoiceNow: reconcile invoice exchange with GST data submission

An InvoiceNow connection can deliver invoices without completing GST data submission to IRAS. The operating process therefore needs separate evidence for commercial exchange and the tax-data population. It also needs eligible purchases and sales that did not arrive through the network.

This guide takes a GST business from phase confirmation to period reconciliation. Use the InvoiceNow reconciliation worksheet for the source inventory, submission dates and exception decisions. The numerical example is synthetic and assumes a simple approved GST treatment.

Confirm the business's notified phase

IRAS phases the requirement. Relevant voluntary-registration groups entered in November 2025 and April 2026; further existing-business groups are scheduled from 2028 onward. The current page explains notification of businesses registered before 2026 and exclusions for specified overseas and reverse-charge-only registrants. Confirm the actual notification and criteria instead of classifying every current GST registrant as newly mandatory in 2026. IRAS: scope, phases and exclusions.

Keep the legal entity, GST identity, notification, implementation date, exclusion assessment and tax approval in one record. If the business has not received a notification, use the official inquiry process and current criteria; do not invent a date from a group company's turnover.

Separate registration/onboarding, feature activation, test acceptance and the mandatory date. Procurement should confirm which solution and Access Point services are provided and who operates any necessary registration or representation steps.

Activate and test the GST submission feature

IRAS's implementation FAQ explicitly states that, if the GST submission feature is inactive, Peppol invoices can continue to be issued to customers without being transmitted to IRAS. Network registration alone therefore does not prove tax-data submission is operating. IRAS: InvoiceNow FAQ, question 1.3.

Ask the provider to demonstrate the business's actual configured service in the intended environment. Capture evidence that a test invoice reached the exchange path and that the applicable data submission produced an observable outcome. Record the identifiers available to your operator and the export needed for reconciliation.

Define who sees rejected or missing results. If the provider performs a transformation, preserve the source and transformed data relationship. A screen saying "sent" must be explained: it may refer to an ERP handoff, an Access Point message or a reporting outcome.

Worksheet: Singapore InvoiceNow period control worksheet

Copy this worksheet for each case. It records decisions and evidence; it does not determine the tax or legal treatment.

Show the worksheet

Use with the Singapore guide. Repeat population blocks; blanks are intended inputs.

Business and service

Population and timing

Reconciliation and recovery

Build the full source population

IRAS generally requires relevant standard-rated and zero-rated supplies/purchases and exempt supplies, with specified exclusions. Its page identifies permitted aggregation for certain POS, simplified-invoice and petty-cash populations and exclusions including reverse-charge transactions and import permits. Reporting scope is not simply "everything exchanged on Peppol" or "every line in the GST return." IRAS: invoice-data scope.

Inventory sales invoices, purchase bills, adjustment notes, retail/POS sources, expense/petty-cash records and other equivalent bills for payment. For each, record inclusion, exclusion or permitted aggregation, with the approved reason and authoritative source system.

Keep original detail underneath aggregates. Give each underlying record one disposition so that it cannot be reported individually and inside an aggregate. Where an invoice arrives through Peppol and is also entered manually, reconcile the identities before posting or reporting another copy.

Use a separate bridge for GST-return items outside the invoice-data population. A difference can be legitimate, but it must be explained. Do not manufacture invoice records for import permits merely to make the two datasets numerically identical.

Set dates using the reporting rule

The current e-Tax Guide requires submission by the earlier of the relevant GST-return filing date and filing due date. It distinguishes the transaction-date rules for supplies and purchases, including the purchase posting-date option under the specified input-tax approach. Approve that basis for the business instead of moving records between periods whenever a user edits an import date. IRAS: adopting the requirement, second edition.

Create a calendar that links the relevant reporting period to the intended return-filing date. An early filing can bring forward the invoice-data deadline. Require the tax-return owner to notify the data-submission operator before filing, rather than after pressing submit.

Store document date, posting date, approved reporting period, transmission time and accepted outcome separately. Late purchase documents and corrections need a documented decision, not an unnoticed shift into whichever period remains open.

Work through a period reconciliation

Assume Merlion Example is already required to submit and tax has approved the populations below. All amounts are SGD, the illustrative standard rate is 9%, and every included purchase is fully deductible under the example's assumptions. There are no foreign-currency or special-regime complications.

The month contains SGD 10,000 net network sales, SGD 2,000 net eligible off-network sales and an approved sales credit of SGD 1,000 net. The net supply total is SGD 11,000 and the illustrative GST is SGD 990. Exchange evidence alone covers only part of this population; the reporting reconciliation must account for all three components.

The included purchase population is SGD 4,000 net, with SGD 360 illustrative GST. Separately, assume an import-permit entry contributes SGD 90 to the approved return calculation but is excluded from invoice-data submission under the scope assessment. The controller records that SGD 90 as an explicit bridge item, with permit evidence, rather than forcing it into the invoice-data file.

The test should show how SGD 990 output GST, SGD 360 purchase GST and the separate approved import amount relate to the return calculation. It does not assume these are the only items in every real return or that every submitted purchase gives full input-tax recovery.

For deadline testing, assume the relevant return is due 30 November, but the authorized tax owner plans to file 20 November. The data-submission plan uses 20 November, the earlier date, with an internal review cutoff before it. If the filing date changes, the owner updates the deadline assessment and checks the outstanding queue.

Recover missing outcomes and correction failures

If the invoice reached the customer but IRAS submission is missing, keep the exchange success and open a reporting exception. Do not issue another commercial invoice to obtain a reporting response. Check activation, mapping and the original identifiers with the provider.

If an invoice is invalid, retain the response and assign the cause. Party data belongs to the master-data owner, tax treatment to tax, and transport/schema issues to integration. An unknown outcome after a timeout needs the supported query/recovery process before retrying.

For credits, returns and amendments, retain the original relationship and verify how the deployed solution submits the adjustment. Make sure a correction is not counted as a new ordinary sale. If the business discovers an error after filing, tax should decide the appropriate correction/disclosure process independently of the connector's retry feature.

Ownership and ready checklist

Tax owns phase, scope, period decisions and filing coordination. AR/AP own source documents and credits. Retail/expense owners own aggregated detail. Integration and the provider own transport and response evidence. The controller owns population and amount reconciliation.

Close only after reviewing source records, individual/aggregate submissions, accepted results and explained exclusions. A net amount can match while a missing invoice and duplicate credit offset each other, so compare identities and counts before totals.

Use mapping tax and reporting obligations for the broader bridge and Peppol process checks for exchange evidence.

Sources checked: 17 October 2026. The current requirement page was updated 8 October 2026; the linked e-Tax Guide is the second edition dated 9 March 2026. Product-specific response names, aggregation eligibility and tax-return treatment require the actual approved implementation.

Vendor documentation is cited only as an example of the level of evidence to ask for; it is not a recommendation or a ranking. This guide is general information, not tax or legal advice. Checked 2026-10-17.

Related: Glossary – abbreviations and terms used in these guides (SAF-T, Peppol, CTC, EN 16931, IFRS and more).

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