GST InvoiceNow Requirements for Singapore Businesses: 2026–2031 Timeline and Preparation Checklist

What businesses need to know

Singapore is progressively making InvoiceNow adoption mandatory for GST-registered businesses.

The requirement has already started for certain newly incorporated companies and voluntary GST registrants. It will be extended progressively to other GST-registered businesses between 2028 and 2031.

Businesses should identify their applicable implementation date early. IRAS indicates that onboarding may take as little as three months, although many businesses may require up to a year depending on their systems and readiness.

What is InvoiceNow?

InvoiceNow is Singapore's nationwide electronic-invoicing network based on the international Peppol standard.

It allows businesses to send and receive structured invoice information directly through participating accounting or finance systems.

An InvoiceNow transaction is different from simply emailing a PDF invoice. The structured invoice information can be transmitted between systems, reducing the need for the recipient to enter the same information manually.

Under the GST InvoiceNow Requirement, GST-registered businesses must use an InvoiceNow-Ready Solution to submit prescribed invoice data to IRAS. The requirement is being implemented in phases.

When must businesses comply?

The implementation timeline published by IRAS is as follows.

From 1 November 2025

The requirement applies to companies that register voluntarily for GST within six months of their incorporation date.

From 1 April 2026

The requirement applies to businesses applying for voluntary GST registration on or after 1 April 2026.

This applies regardless of:

• The business's incorporation date
• Whether it is a company, partnership or another business structure
• The amount of its annual supplies

A business considering voluntary GST registration should therefore include InvoiceNow readiness in its registration plan.

From 1 April 2028

The requirement will apply to:

• Businesses applying for compulsory GST registration on or after 1 April 2028
• Existing GST-registered businesses with total annual supplies of S$200,000 or less

From 1 April 2029

The requirement will apply to existing GST-registered businesses with total annual supplies of S$1 million or less.

From 1 April 2030

The requirement will apply to existing GST-registered businesses with total annual supplies of S$4 million or less.

From 1 April 2031

The requirement will apply to existing GST-registered businesses with total annual supplies exceeding S$4 million.

For existing GST-registered businesses, total annual supplies generally refers to the value of standard-rated, zero-rated and exempt supplies reported in Box 4 of the GST returns for prescribed accounting periods ending in calendar year 2025.

Businesses should verify their applicable implementation date against the latest IRAS guidance.

Are any businesses excluded?

Based on current IRAS guidance, the GST InvoiceNow Requirement does not apply to:

• Overseas entities, including overseas vendors registered under the Overseas Vendor Registration pay-only or full regime
• Businesses liable to register for GST wholly because of the reverse-charge regime

These exclusions should be considered carefully. A business should not assume it is excluded merely because it has overseas transactions or applies reverse charge to some purchases.

What information must be submitted?

In general, businesses must submit invoice data relating to transactions reported in their GST returns, including:

• Standard-rated supplies and purchases
• Zero-rated supplies and purchases
• Exempt supplies
• Sales and tax invoices
• Simplified tax invoices
• Serially numbered receipts
• Debit notes
• Credit notes

IRAS permits certain information to be aggregated, including qualifying data from point-of-sale systems, supplies for which simplified tax invoices are issued and petty-cash purchases.

Certain transactions do not require invoice data to be submitted. Examples presently identified by IRAS include:

• Transactions with no underlying supply or purchase but which must be reported for GST purposes
• Reverse-charge transactions
• Certain exempt financial services
• Exchanges or loans of digital payment tokens
• Import permits relating to the importation of goods

Businesses should map their transaction types carefully instead of assuming that every entry in the GST return is treated in the same way.

When must invoice data be submitted?

Invoice data must generally be submitted to IRAS by the earlier of:

• The date the relevant GST return is filed
• The filing due date of that GST return

The relevant GST return is the return covering the accounting period in which the transaction occurs.

This means a business should not wait until after filing its GST return to investigate incomplete or rejected invoice submissions.

A regular reconciliation between the accounting records, submitted InvoiceNow data and GST return should form part of the GST-closing process.

How can a business get started?

Businesses using off-the-shelf accounting software

A business should:

1. Check whether its accounting or finance software is an accredited InvoiceNow-Ready Solution.
2. Contact the software provider about activating InvoiceNow.
3. Register the business in the Singapore Peppol Directory using its UEN.
4. Obtain its Peppol ID.
5. Activate the feature for submitting invoice data to IRAS.
6. Test both sales and purchase transactions.
7. Review rejected, incomplete or duplicated submissions.
8. Reconcile the submitted information against the GST return.

Businesses using an in-house system

A business operating its own enterprise or accounting system should contact an IMDA-accredited Access Point Provider.

The business will generally need to:

1. Register for a Peppol ID.
2. Connect its system through the Access Point Provider.
3. Map its transaction data to the required format.
4. Activate the IRAS submission function.
5. Test the completeness and accuracy of transmissions.
6. Establish procedures for handling failed submissions and system downtime.

The accounting, finance, tax and technology teams may need to work together during implementation.

Is support available?

Based on current IRAS guidance, support includes:

• A GST InvoiceNow Transition Grant of S$1,000 for eligible SMEs with annual supplies of S$4 million or less
• A GST InvoiceNow Transition Grant of S$5,000 for eligible larger businesses with annual supplies exceeding S$4 million
• An InvoiceNow Queen Bee Grant of S$25,000 for eligible larger businesses
• Free-of-charge solution packages providing basic e-invoicing capabilities

Grant availability, qualification conditions and application periods may change. Businesses should confirm the latest position directly with IMDA before making an implementation decision.

IRAS currently states that free-of-charge solution packages will be available up to 31 March 2031.

InvoiceNow does not replace GST controls

Using InvoiceNow does not transfer responsibility for GST compliance to the software provider or IRAS.

A GST-registered business remains responsible for:

• Issuing valid tax invoices
• Applying the correct GST treatment
• Reporting supplies in the correct accounting period
• Claiming input tax only when the conditions are satisfied
• Filing accurate GST returns
• Retaining proper records for at least five years
• Correcting errors when identified

Automation can transmit information efficiently, but incorrect information may also be transmitted efficiently. Proper review and reconciliation therefore remain essential.

Internal controls businesses should establish

Customer and supplier information

• Verify customers' and suppliers' UEN and GST-registration status.
• Restrict who may create or amend customer and supplier records.
• Review changes to GST numbers and bank-account information.
• Prevent duplicate customer or supplier records.

Invoice processing

• Require sequential and unique invoice numbers.
• Check the GST rate and tax code applied.
• Separate sales invoices, credit notes and debit notes correctly.
• Prevent duplicate invoices from being transmitted.
• Review invoices rejected by the network.

Purchase processing

• Confirm that the supplier is GST-registered before claiming input tax.
• Check that the business has the required supporting documents.
• Identify private, disallowed or partially claimable expenses.
• Review invoices recorded in a different period from their issue date.

GST reporting

• Reconcile InvoiceNow sales data to revenue and output tax.
• Reconcile purchase data to expenses, assets and input tax.
• Investigate differences before filing the GST return.
• Retain evidence of review and approval.
• Document the treatment of transactions not requiring submission.

Access and business continuity

• Restrict user access according to job responsibilities.
• Retain an audit trail of amendments and approvals.
• Establish procedures for failed or delayed transmissions.
• Maintain an alternative process during system downtime.
• Review the service provider's data-security and retention arrangements.

Common misconceptions

We already email PDF invoices, so we are compliant

Emailing a PDF does not necessarily mean that the business is using an accredited InvoiceNow-Ready Solution or submitting the required invoice information to IRAS.

Our deadline is in 2030, so we can wait

System selection, data cleaning, configuration and testing may take several months. Early preparation reduces the risk of rushed implementation.

InvoiceNow will prepare the GST return for us

InvoiceNow facilitates the submission of invoice information. The business must still review its accounting records and file an accurate GST return.

Only sales invoices are affected

The requirement generally covers prescribed information relating to both supplies and purchases.

The accounting software provider is responsible for any GST errors

The business remains responsible for its invoices, GST treatment, records and returns.

Preparation checklist

1. What is our mandatory implementation date?
2. Are we already using an InvoiceNow-Ready accounting system?
3. Is our business registered in the Singapore Peppol Directory?
4. Have we activated invoice-data submission to IRAS?
5. Are customer and supplier records complete and accurate?
6. Are GST codes applied consistently?
7. Which transaction types must be submitted?
8. Which transactions may be aggregated or excluded?
9. How will rejected submissions be investigated?
10. How will InvoiceNow data be reconciled to the GST return?
11. Who will review and approve the reconciliation?
12. What happens if the system becomes unavailable?
13. Are we eligible for a grant or free solution?
14. Have relevant employees received appropriate training?

How LN Corporate Services can assist

LN Corporate Services can assist businesses with assessing their implementation timeline, reviewing accounting records and GST codes, cleaning customer and supplier data, establishing invoice-processing procedures, reconciling InvoiceNow information to GST returns, preparing GST returns and developing appropriate accounting controls.

Technical implementation services may be provided by appropriately qualified external solution providers where required.