If you’re running a business in Singapore, you’ll need a tax identification number (TIN). Businesses in the country require a TIN to register with the Inland Revenue Authority of Singapore (IRAS), open a bank account, and issue an invoice to a client.

Singapore doesn’t have a single, dedicated tax ID system the way some countries do. Instead, it relies on identifiers that already exist for other purposes: your National Registration Identity Card (NRIC) or Foreign Identification Number (FIN) if you’re an individual, and your Unique Entity Number (UEN) if you’re operating as a company, partnership, or other registered entity. Singapore’s UEN system launched in 2009 and 51 government agencies adopted it to replace the separate ID numbers each agency issued in the past.

Below, we’ll explain what counts as a TIN in Singapore, how the different ID numbers relate to each other, and when you’ll need to produce one.

Key takeaways

• Instead of issuing a TIN in name, Singapore relies on a person’s or entity’s existing NRIC, FIN, or UEN to identify them as a taxpayer.

• Agencies previously issued their own separate registration and tax numbers. But in 2009, those were replaced with the UEN, which now serves as the tax reference number for businesses.

• Which identifier applies depends on who’s filing: individuals use their NRICs or FINs, while companies, sole proprietorships, and partnerships use their UENs.

What is a TIN in Singapore?

A TIN is a unique number used by the government to identify a taxpayer. In Singapore, that TIN can take different forms depending on the taxpayer’s circumstances. You’ll need it to file income tax as an individual, open a business bank account, or register for goods and services tax (GST).

What types of TINs are used in Singapore?

There are several identifiers used as TINs in Singapore. Each one is issued by a different agency for a different category of taxpayer, and each follows its own format.

NRIC

The Immigration & Checkpoints Authority (ICA) issues this nine-digit number to Singapore citizens and permanent residents. It starts with an S or T, followed by seven digits and a checksum letter that helps catch typing or scanning errors.

FIN

The ICA issues this nine-digit number for long-term immigration passes (e.g., dependent’s pass, student’s pass, long-term visit pass), and the Ministry of Manpower issues it for work passes. Any FIN that’s issued after January 2022 starts with an M; F and G prefixes remain valid on older FINs.

UEN

The Accounting and Corporate Regulatory Authority (ACRA) issues this 9- or 10-digit number to companies, limited liability partnerships, sole proprietorships, and other registered entities at the point of registration. The applicable format depends on when and how the entity registered (e.g., 201912345A for a company incorporated in 2019).

GST registration number

The IRAS issues this number once a business registers for GST, either voluntarily or after its taxable turnover exceeds 1 million Singapore dollars in a 12-month period. But typically, the IRAS uses the entity’s existing UEN as a substitute instead of issuing a separate one.

When do businesses need a TIN in Singapore?

You’ll need a TIN before your first filing deadline. It’s also required for a range of business and compliance touchpoints, including:

• Company incorporation and registration: ACRA assigns your UEN the moment your business registration gets approved; it stays with the entity for its entire life.

• Income tax and GST filing: The IRAS requires your UEN, NRIC, or FIN on every income tax return, GST return, and piece of correspondence, including e-filing through the myTax Portal.

• Invoicing and recordkeeping: Tax invoices for GST-registered supplies need to show your GST registration number, which is why B2B invoices in Singapore usually display the issuing business’s UEN.

• Bank account opening and payment setup: Banks and payment providers verify your UEN during onboarding since it confirms your business is legally registered and lets them match your account to the right tax reporting profile.

• Cross-border and CRS reporting: If a bank or financial institution determines you’re a tax resident of a country Singapore has a Common Reporting Standard (CRS) exchange agreement with, it reports your account details to the IRAS. That agency shares the information with the relevant partner tax authority.

How does a TIN differ from a UEN in Singapore?

Before 2009, a Singapore business could hold several different numbers: one for registration from the Registry of Companies or Registry of Businesses, another for tax from the IRAS, and sometimes a third from the Central Provident Fund Board or Singapore Customs.

When ACRA rolled out the UEN, these separate identifiers were folded into one number that every government agency, including the IRAS, recognises. The UEN serves as a TIN for a Singapore-registered company, partnership, or sole proprietorship. Since a sole proprietorship isn’t a separate legal entity from its owner, it might have a UEN for the business but use a personal NRIC or FIN for individual income tax. Both ACRA and the IRAS use the UEN to confirm an entity’s registration status and tax standing, which means it can also be used to check whether a business you’re working with is legitimate.

How does a TIN fit into digital financial operations in Singapore?

Your GST treatment usually depends on where that buyer is and whether you’re registered. Your UEN ties the transaction back to your tax profile with the IRAS.

Here’s how treatment differs across transaction types:

e-commerce and GST treatment

Your GST obligations on an online sale depend on the buyer’s location and your registration status. Checkout systems need to capture the right details to apply tax correctly rather than treat every sale the same way.

Online invoicing and InvoiceNow

A GST-registered business must show its GST registration number on every tax invoice. The IRAS has been pushing adoption of InvoiceNow, the national e-invoicing network built on the Peppol standard, which routes structured invoice data, including the seller’s UEN, between accounting systems.

Cross-border transactions

You’ll need an overseas vendor registration to sell into Singapore from abroad. Buying services from overseas can activate the reverse charge mechanism, but only for GST-registered businesses that aren’t entitled to full input tax recovery. Both types of international transactions hinge on correctly identifying which party is registered for GST and what their registration number is.

best practices for Compliance

If you get an identifier wrong or fail to capture it at checkout, that skews tax calculation on an order and complicates reporting later on. Systems need to check GST registration status, apply the correct tax treatment, and record the UEN or tax reference number tied to each transaction before the sale closes out.

How can businesses manage TIN requirements in Singapore?

Adopt these practices for handling TINs in Singapore to avoid additional work later:

• Verify UENs through ACRA’s Bizfile: Before you onboard a new business customer or supplier, you can confirm its UEN is valid and check the entity’s registration status through ACRA’s Bizfile portal. This helps prevent disputes over invoices or tax filings.

• Keep tax reference numbers consistent across invoicing and accounting: A business that uses a slightly different invoice format from what’s registered with the IRAS can encounter mismatches during GST filing; you’ll want to match invoice templates to the exact UEN on file.

• Build GST registration checks into checkout and billing: Since GST treatment depends on registration status and buyer location, checkout and billing systems that look up and apply the right tax rate automatically reduce the risk of under- or overcharging.

• Track filing deadlines tied to your tax reference number: Since the IRAS ties GST filing periods and income tax deadlines to your registered number, businesses that run multiple entities need a way to track which filings apply to which UEN.

Tools like Stripe Tax can help you calculate tax across Singapore and other markets where a business sells. Using the buyer’s location and the business’s registration status, Stripe Tax applies the correct GST or value-added tax (VAT) treatment at checkout. It flags where a growing business might pick up new tax obligations and provides the transaction-level reporting needed for filing with the IRAS.

How Stripe Tax can help

Stripe Tax reduces the complexity of tax compliance so you can focus on growing your business. Start collecting taxes globally by adding a single line of code to your existing integration, clicking a button in the Dashboard, or using our powerful application programming interface (API).

Stripe Tax helps you monitor your obligations and alerts you when you exceed a tax registration threshold based on your Stripe transactions. It can also register to collect tax on your behalf in the US, automate US filings in the Dashboard, and manage global filings through trusted partners. Stripe Tax automatically calculates and collects sales tax, VAT, and GST on:

• Digital goods and services in all US states and over 100 countries
  
• * Physical goods in all US states and 42 countries
  

Stripe Tax can help you:

• Understand where to register and collect taxes: See where you need to collect taxes based on your Stripe transactions. After you register, switch on tax collection in a new state or country in seconds. You can start collecting taxes by adding one line of code to your existing Stripe integration, or add tax collection with the click of a button in the Stripe Dashboard.

• Register to pay tax: If you need to register for sales tax in the US, let Stripe manage your tax registrations. You’ll benefit from a simplified process that prefills application details—saving you time and simplifying compliance with local regulations. If you need help registering outside of the US, Stripe partners with Taxually to help you register with local tax authorities.

• Automatically collect tax: Stripe Tax calculates and collects the right amount of tax owed, no matter what or where you sell. It supports hundreds of products and services and is up-to-date on tax rules and rate changes.

• Simplify filing: Stripe Tax automates US filings in the Dashboard, powered by TaxJar. For global filings, Stripe Tax seamlessly integrates with filing partners, so your global filings are accurate and timely. Let our partners manage your filings so you can focus on growing your business.

Learn more about Stripe Tax or get started today.