Most GST-registered businesses in Singapore think about GST once a quarter, when the return is due. The questions that matter during an IRAS audit, however, are answered by records created months or years earlier. This guide on GST record‑keeping requirements and how to stay ready for an IRAS audit explains what you must keep, for how long, and how to organise it so that a review letter does not turn into a scramble.
Raffles Corporate Services works with a panel of experienced Singapore law firms who offer cost-effective and efficient legal service and advice. This article is general information only and is not legal advice.
Good records let you support every input tax claim, justify every zero-rated sale and correct errors before IRAS finds them.
Who this applies to
These requirements apply to every business registered for GST with IRAS, whether registration was compulsory or voluntary. That includes:
- Private limited companies, sole proprietorships and partnerships registered for GST
- Foreign companies and branches registered for GST in Singapore
- Overseas vendors registered under the Overseas Vendor Registration regime for digital services and low-value goods
- Businesses that have recently deregistered, which must still keep records for past periods
If you are not yet GST-registered but are approaching the SGD 1 million taxable turnover threshold, it is worth building these habits now.
Key rules and requirements in Singapore
The Goods and Services Tax Act 1993 and its regulations require GST-registered businesses to keep proper records of all business transactions that affect, or may affect, their GST position. The main points are set out below.
Retention period
Records must generally be kept for at least five years. In practice, many companies keep them longer, because the Companies Act also requires accounting records to be retained for five years from the end of the financial year in which the transactions were completed, and ongoing disputes or claims may extend the period you need.
What you must keep
- Tax invoices and simplified tax invoices issued and received
- Credit notes and debit notes
- Receipts, payment vouchers and bank statements
- Import permits and customs documentation for goods imported into Singapore
- Export documents and shipping evidence supporting zero-rated supplies
- Contracts and agreements for significant or unusual supplies
- Your GST account, showing how output tax and input tax figures in each GST F5 return were derived
- General ledger, sales and purchase listings, and the financial statements
Form and language
Records may be kept on paper or electronically, provided electronic records are complete, accurate, readable and retrievable when IRAS asks for them. Records in a language other than English should be translatable on request. If you scan paper documents and discard the originals, your scanning process must produce a reliable, legible copy that cannot be easily altered.
Tax invoice rules
A GST-registered supplier must issue a tax invoice to GST-registered customers within 30 days of the time of supply. Your input tax claims depend on holding a valid tax invoice (or an import permit for imports) that shows the correct details, including the supplier’s GST registration number. Simplified tax invoices may be used where the total amount payable, including GST at 9%, does not exceed SGD 1,000.
Consequences of poor records
Failing to keep proper records is an offence under the GST Act and can lead to fines. More commonly, the practical cost is that IRAS disallows input tax claims or zero-rating that you cannot support, and then imposes penalties and late payment charges on the resulting tax.
Step-by-step process
A simple, repeatable routine keeps your records audit-ready all year.
- Step 1: Set up a clear filing structure. Organise documents by GST period and by type, such as sales, purchases, imports and exports. If you use cloud accounting software, attach the source document to each transaction.
- Step 2: Check invoices on receipt. Before recording a supplier invoice, confirm it shows the supplier’s GST registration number, the date, a description of the supply and the GST amount. Chase the supplier for a corrected invoice straight away if anything is missing.
- Step 3: Apply the correct tax codes. Map every transaction to the right code, whether standard-rated, zero-rated, exempt or out-of-scope. Most GST errors start with an incorrect code at data entry.
- Step 4: Collect zero-rating evidence as you go. For exported goods and international services, keep the export permit, bill of lading or airway bill, and evidence of payment. Obtaining these months later is often impossible.
- Step 5: Reconcile before filing. Each quarter, reconcile the GST control account to the figures in your GST F5 and tie total supplies back to revenue in the general ledger.
- Step 6: Keep a working file for each return. Save the reconciliation, adjustments and supporting notes for each period. This file is usually the first thing an IRAS auditor will ask for.
- Step 7: Correct errors promptly. If you discover a mistake, use the GST F7 on the IRAS myTax Portal to disclose it. Voluntary disclosure made early generally attracts more favourable treatment than an error found during an audit.
Common mistakes to avoid
- Claiming input tax without a valid tax invoice. A receipt or statement that lacks the supplier’s GST registration number or the GST amount will usually not support a claim.
- Claiming GST on blocked expenses. Input tax on items such as club subscriptions, medical expenses for staff (unless obligatory under the Employment Act or Work Injury Compensation Act) and motor car expenses is generally disallowed.
- Zero-rating without evidence. Treating a sale as an export without the supporting documents exposes you to output tax at 9% on the full value.
- Losing data during a system change. Migrating to new accounting software without exporting historical records and attachments is a common and avoidable problem.
Practical examples
Example 1: A trading company with exports
A Singapore distributor zero-rates shipments to Malaysia. During a review, IRAS asks for export evidence for twelve invoices. The company kept commercial invoices but not the export permits or shipping documents for four of them. IRAS treats those four sales as standard-rated, and the company must pay 9% GST on their value from its own margin, along with potential penalties.
Example 2: A consultancy with good habits
A professional services firm attaches every supplier invoice to its cloud accounting entries and keeps a reconciliation workbook for each quarter. When IRAS selects the company for a routine check, the finance manager exports the GST listings and supporting documents within two days. The review closes with no adjustments.
Example 3: Discovering an error before IRAS does
A company finds that it has claimed input tax on staff medical insurance for two years. It quantifies the over-claim, files a GST F7 and pays the difference. Because the disclosure was voluntary and prompt, the company is in a far better position than if the error had surfaced during an audit.
How a corporate secretary can help
GST compliance sits at the meeting point of bookkeeping, tax and governance. A corporate secretary and accounting team can help by:
- Setting up a document filing structure and month-end checklist suited to your business
- Reviewing tax codes and reconciling GST accounts before each GST F5 is filed
- Preparing the supporting working file for each return
- Assisting with responses to IRAS queries and voluntary disclosures
- Aligning GST records with your annual financial statements, ACRA annual return and corporate income tax filings
Raffles Corporate Services supports companies with accounting, GST filing, corporate tax, payroll and corporate secretarial compliance, so that records stay consistent across every regulator you deal with.
Frequently Asked Questions
How long must I keep GST records in Singapore?
Generally at least five years. Keep them longer if a transaction is under dispute, subject to an ongoing contract, or relevant to a later period.
Can I keep only digital copies of invoices?
Yes, provided the electronic records are complete, legible and can be produced when IRAS requests them. Your scanning and storage process should be reliable and protect records from alteration.
What happens if I lose a supplier’s tax invoice?
Ask the supplier for a copy marked as such. Without a valid tax invoice, you may not be able to support the input tax claim if IRAS reviews it.
What does an IRAS GST audit usually involve?
IRAS typically requests listings, reconciliations and a sample of source documents, and may ask questions about your business processes. Some reviews are desk-based; others involve a visit to your premises.
Key takeaways
- GST-registered businesses must keep complete records supporting every figure in their GST returns, generally for at least five years.
- Valid tax invoices and import permits are the foundation of every input tax claim.
- Zero-rated supplies need export or international service evidence gathered at the time of the transaction.
- A quarterly reconciliation and a working file for each return make IRAS reviews far easier to handle.
- Errors should be corrected through a GST F7 as soon as they are found.
- Requirements may change, so always check the latest guidance from ACRA, IRAS or MOM, or consult a professional adviser.
If you would like to find out more about how Raffles Corporate Services can assist with your company’s compliance and corporate secretarial requirements, please get in touch with the team at [email protected].
Yours sincerely,
The editorial team at Raffles Corporate Services
Disclaimer: This does not constitute legal advice. If you require legal advice, please contact a lawyer.