Fraud chain and tax-loss example
Missing Trader Fraud uses contrived chains directed by a controlling mind. A missing trader charges GST but does not account/pay it, buffers trade onward, and an exporter seeks input credit/refund against zero-rated exports. Shell, shelf or fictitious traders and nominee directors may feature. Goods can circulate again as carousel fraud or exist only on paper; any taxable goods/services can be involved. In the 9% example, A sells for S$1 m and keeps S$90,000 GST; B sells for 1.5 m, charges 135,000 and pays 45,000 net; C exports and claims 135,000. IRAS loses 90,000. Extra buffers and legitimate businesses can obscure the connection.
Knowledge Principle from 2021
From 1 January 2021, GST Act 20(2 A)/(2 B) denies input tax where the taxable person knew or should have known of an arrangement causing public-revenue loss, even if other claim conditions were satisfied. The objective should-have-known test combines reasonable risk in incoming/outgoing supply circumstances with failing reasonable checks, or checking but reaching an unreasonable negative conclusion, no conclusion, or being unable to rule out the arrangement. Reasonable steps and a conclusion a reasonable person would make protect the claim under this principle.
Three pillars and proportionate monitoring
Identify/assess risk, perform appropriate due diligence, then respond to findings. The guide’s examples are not an exhaustive checklist. One indicator alone is not necessarily fraud, but several suggest suspicion. Match checks to transaction/business risk and re-assess when representatives/products change, volumes/value grow unusually or adverse partner news appears. Existing checks can be relied on absent red flags/triggers, with ongoing monitoring proportional to risk.
Risk area A: counterparties
Indicators include new suppliers offering high-value deals, trade inconsistent with their normal business, pre-arranged matching buyers/sellers, minimal sourcing or decisions controlled by others, common/inconsistent addresses, unnecessary evasive parties, poor business/financial presence or ownership changes, and representatives hard to authenticate because instructions are verbal or instant messages. Verify profiles against reliable registers/websites, trade/product knowledge, references and credit/background checks; visit premises. Record representatives’ names, roles and contacts and verify identity, capacity and reason for third-party involvement with the principal.
Risk area B: deal commerciality
High volume/value beyond market demand, no formal high-value contract, fixed margins regardless of time/quantity/specification, unusual negotiation and near-zero risk/back-to-back deals without inventory or sourcing are warning signs. Check demand, market price, realistic supply capacity, trade geography, the reason for low risk and your actual value-add. The first expanded-chain example describes an exporter offered guaranteed profit and customer prepayment while asked to finance purchase GST and claim a refund; easy profit does not establish genuine commerciality.
Risk area C: money flows
Unusually low credit exposure, pay-supplier-only-after-customer terms, full prepayment, cash-only deals, many small payments with large cumulative value, offshore/third-party supplier accounts and local agents paying for customers require scrutiny. Compare terms with practice, obtain commercial explanations, identify third-party relationships and reasons, and reconcile names, addresses, destinations and ports in financial/trade records.
Risk area D: goods and movement
Unclear origin/brand/manufacturer, no reliable warranty/quality assurance, uninsured high-value shipments and unclear transit liability are warning signs. Verify physical goods, working condition and invoice match, reviews, recourse, insurance/warranty/service agreements. Record forwarder, transport details, title/liability and actual customer receipt. Investigate description/destination/quantity discrepancies, implausible weight or unusual vessel size/type.
Example 2: doing no further checks
Engineering company X accepted a former colleague’s computer-parts export opportunity with 2% guaranteed margin, about S$500,000 monthly sales, ten exports averaging 50,000 each and 2–3 day turnaround. Customers paid through a third party before delivery; X paid supplier only afterward, with no warranty/insurance assurance. X did no further checks and IRAS denied input under should-have-known. The example proposes checks across all four risk areas. Its later due-diligence table says 50,000 permonth, inconsistent with the main narrative’s 500,000 permonth/50,000 perexport; the transaction facts above follow that main narrative.
Example 3: checks ignored
Experienced electronics X checked supplier Y and found poor credit, registered beauty-product rather than electronics activity, unexplained steady foreign demand, refusal to identify exporters before commitment and refusal to disclose goods source. Despite same-day direct delivery and supplier payment only after customers, X pursued the attractive deal. Performing checks did not cure ignoring adverse results; input was denied.
Response and evidence
Make further enquiries when checks are unsatisfactory and avoid suspected MTF deals. For proceeded transactions, show reasonable steps and a reasonable negative conclusion grounded in assessed risks and results. Keep risk assessments, checks, responses, precautions and decisions readily available. This creates accountability and supports timely complete accurate audit responses; superficial ticking of boxes is insufficient. Non-immediate parties need not be checked where there is no connection/direct dealing, but immediate parties and transaction integrity still matter.
Audit, decisions and appeals
IRAS informs the business of Knowledge-Principle audit/investigation and, where applicable, withholding refund within three months after receiving all requested information. Complex multi-party inquiries can take time. It examines timeliness/adequacy of checks, findings, conclusions and responses, without demanding more than reasonable. Denial comes with reasons. GST Act 49 objection must be written, detailed, signed/dated and within 30 days of Notice of Assessment. After review decision, lodge written appeal notice to GST Board of Review secretary within 30 days, then petition grounds within a further 30 days after lodging notice.
Surcharge and reporting suspicion
Should-have-known denial adds 10% of denied input tax: S$50,000 denied means 5,000 surcharge on top of assessed tax. Actual knowledge can lead to prosecution under GST Act 59/62 and conviction penalties. Vague or withheld normal information warrants considering withdrawal. Report suspected arrangements to [email protected] or the Reporting Tax Evasion template; general enquiries go to GST Division through IRAS Contact Us.
Appendix A: governance and two flowcharts
Assign an accountable MTF risk/process owner within existing governance. For new/existing counterparties and proposals, assess high risk; high risk leads to checks, then red flags and an accept/decline decision. No high risk or no red flags leads to documented assessment and periodic review; unacceptable risk leads to termination/decline. Ongoing review/monitoring tests red flags, then enhanced diligence; a credible reasonable explanation leads to documentation/review, no explanation to termination. This flowchart does not override the main advice to avoid suspected fraud. Train staff at all levels, particularly procurement/sales, logistics/accounts and compliance/internal audit.
Edition changes
Fourth edition 30 January 2026 makes editorial changes to 1.2,6.3,7.3 and FAQA 2. Earlier 2023/2024 updates changed example GST from 7% to 8% then 9%. The prevention framework is risk-based and the examples non-exhaustive; the guide is broader than particular high-value/lightweight goods commonly used by fraudsters.
Official source
This article independently explains the substantive contents of the official PDF, including the relevant conditions, procedures and annexes. The linked document remains the authoritative source for its original wording, and later changes should be checked separately.
Read the official PDF ↗