Filing corporate taxes in Singapore is a must for all companies, whether resident or non-resident, and is overseen by the Inland Revenue Authority of Singapore (IRAS). The corporate tax rate is a flat 17%. Still, with schemes like the Start-Up Tax Exemption (SUTE), Partial Tax Exemption (PTE), and industry-specific incentives, many businesses, especially startups and SMEs, pay a much lower effective rate.

Corporate tax in Singapore follows a preceding year basis, meaning profits from one financial year are taxed in the following Year of Assessment (YA). Companies must file Estimated Chargeable Income (ECI) within three months after their financial year-end, unless exempt, and submit Form C, C-S, or C-S (Lite) by 30 November of the YA. Missing deadlines, miscalculating income and applicable deductions, or misclassifying expenses can result in penalties, fines, or audits.

Singapore’s single-tier tax system ensures dividends are not taxed twice, making it highly attractive for investors. To stay compliant and avoid costly errors, many businesses engage professional corporate tax services like Lanturn for planning, GST filing, and timely submissions. With a transparent tax regime, global competitiveness, and pro-business policies, Singapore remains one of the best business hubs to run and grow a company.

Filing corporate taxes is one of the most critical steps involved when reaching the end of a company’s financial year. Keeping up with all the laws can be time-consuming; yet, if you fail to do so, you may end up dealing with expensive penalties. 

Whether you are a new business owner or not, Singapore corporate taxes can be tricky to navigate. With many different requirements and documentation to complete, it helps from time to time to have a quick guide to help you with filing corporate taxes correctly.

What is Corporate Tax in Singapore?

Corporate tax in Singapore refers to the tax imposed on the income earned by companies that operate in or are registered in Singapore.

• It is administered and collected by the Inland Revenue Authority of Singapore (IRAS), the government body responsible for ensuring compliance with the country’s tax laws.
• Corporate tax applies to a company’s chargeable income, in simple words, its taxable income after deducting allowable business expenses, capital allowances, and available reliefs.

Singapore’s corporate tax system is competitive and business-friendly. With a relatively low headline rate, coupled with various exemptions and reliefs, the country consistently ranks among the top places in the world for ease of doing business.

According to the World Bank’s last Ease of Doing Business Report and data from IRAS, Singapore remains a central global hub for entrepreneurs, SMEs, and multinational businesses alike.

Who Needs to Pay Corporate Tax?

All companies registered in Singapore, whether they are resident or non-resident, are required to pay corporate income tax in Singapore on their taxable income. However, the scope of taxation depends on a company’s tax residency:

• Resident companies (those whose control and management are exercised in Singapore) are taxed on income earned within Singapore and foreign-sourced income that is remitted into Singapore. Resident companies are also eligible for a wide range of exemptions, reliefs, and double taxation agreements.
• Non-resident companies are only taxed on income sourced from Singapore. They may also be subject to Withholding Tax on certain types of income paid to non-resident entities, such as royalties, interest, or technical service fees.

Entities like sole proprietorships and partnerships are not subject to corporate tax in Singapore but instead fall under the individual income tax framework.

Overview of the IRAS Corporate Tax System

The IRAS corporate tax system is based on a preceding year basis, meaning that income earned in one financial year is assessed and taxed in the following Year of Assessment (YA). For example, profits earned in the financial year ending 31 December 2024 will be taxed in YA 2025.

Key elements of the system include:

• Estimated Chargeable Income (ECI): An estimate of a company’s taxable income that must be submitted within 3 months after the financial year-end.
• Form C and Form C-S: Detailed annual tax returns that provide the final declaration of chargeable income.
  • Form C-S: Singapore-incorporated companies with annual revenue of $5 million or below
  • Form C-S (Lite): Singapore-incorporated companies with annual revenue of $200,000 or below
  • Form C: All companie

IRAS also employs a single-tier taxation system, meaning dividends distributed to shareholders are not taxed again at the individual level.

Singapore Corporate Tax Rate and System

Current Corporate Tax Rate in Singapore

The Singapore corporate tax rate is a flat 17%. This rate applies to both resident and non-resident companies (IRAS). This rate is among the lowest in Asia and the world, making Singapore a preferred business hub for entrepreneurs and venturers seeking to establish regional headquarters or grow their operations.

However, due to tax incentives and reliefs, the effective tax rate for many companies, particularly startups and SMEs, is significantly lower than the headline 17%.

Single-Tier Corporate Income Tax System

Singapore follows a single-tier corporate income tax system. Under this framework:

• Corporate tax paid on profits is considered final.
• Dividends distributed to shareholders are exempt from further taxation.

Since profits are only taxed once, this creates a transparent and investor-friendly tax landscape.

Exemptions and Incentives for Startups & SMEs

To encourage entrepreneurship and innovation, Singapore offers various exemptions and incentives:

• Start-Up Tax Exemption (SUTE): Newly incorporated companies can claim substantial exemptions on the first three consecutive Years of Assessment (YA). Currently, startups can receive a 75% exemption on the first SGD 100,000 of chargeable income and a further 50% exemption on the next SGD 100,000. These exemptions hold for qualifying companies in Singapore, meeting specific requirements as follows:
  • Incorporation: The company must be registered as a private limited company with the Accounting and Corporate Regulatory Authority (ACRA) in Singapore.
  • Tax Resident: The company must be a Tax Resident in Singapore for the relevant Year of Assessment (YA).
  • Shareholding Criteria: The startup shouldn’t have more than 20 shareholders, and at least one shareholder must hold at least 10% of the ordinary shares.
• Partial Tax Exemption (PTE): Available to all companies, this provides a 75% exemption on the first SGD 10,000 of chargeable income and a 50% exemption on the next SGD 100,000 for all assessment years.
• Industry-specific incentives: Sectors like technology, financial services, fintech, and green energy benefit from the targeted corporate tax services in Singapore, including specific grants and reductions.

These schemes significantly reduce the tax burden for startups and SMEs, making Singapore a supportive and conducive environment for business growth.

Different Singapore Corporate Tax Submissions

Businesses in Singapore must comply with two primary types of tax submissions:

1. Estimated Chargeable Income (ECI): This is the company’s estimated taxable income for the year, which must be filed within 3 months of the financial year-end. Filing the ECI helps IRAS better estimate tax collections for the year.
2. Form C or Form C-S: These are annual income tax returns that provide full details of the company’s financial position, revenue, and expenses. Form C is more comprehensive, while Form C-S is simplified and available to smaller qualifying companies that are not required to submit financial statements and tax computations.

Companies must ensure accuracy in these submissions, as errors can lead to penalties or audits.

Corporate Tax Filing Deadlines in Singapore

ECI Filing Deadlines

Companies must file their ECI within 3 months of the end of their financial year. For example, a company with a financial year ending on 31 December must submit its ECI by 31 March of the following year.

You are required to submit ECI unless you meet the IRAS waiver conditions, which are as follows:

• Annual revenue (revenue from the company’s primary source of income) is $5 million or below for the financial year; and
• ECI is nil for the Assessment Year.
• The ECI should be the amount before deducting the exempt amount under the partial tax exemption scheme or the tax exemption scheme for new start-up companies.

Form C and C-S Filing Deadlines

The deadline for filing Forms C and C-S for corporate tax filing in Singapore is as follows:

• Form C-S/ Form C-S (Lite)/ Form C must be filed by 30 Nov every year to avoid enforcement actions such as composition or summons. The filing due date of 30 November provides companies with at least 11 months to file after the accounts are closed. The deadline for filing your Corporate Income Tax Return (Form C-S/ Form C-S (Lite)/ Form C) for the Year of Assessment (YA) 2025 is 30 Nov 2025.
• Companies must comply with these Singapore corporate tax filing deadlines to avoid penalties, which can range from late filing fees, composition, or court summons for persistent non-compliance.

Common Mistakes in Corporate Tax Filing

Missing Deadlines

One of the most common and grave mistakes businesses make is missing the ECI or Form C/C-S deadlines. IRAS imposes penalties for late submissions, which may include financial penalties, late payment interest, or even legal consequences (court summons) for repeated breaches.

Incorrect ECI Calculations

Some businesses inaccurately calculate their ECI, either overstating or understating their income. Incorrect calculations can result in underpayment or overpayment of taxes, both of which can create complications. Engaging professional corporate tax filing services like Lanturn can help reduce these risks.

Other mistakes include:

• Misclassifying expenses (claiming non-deductible costs).
• Failing to consider tax exemptions properly.
• Overlooking rules regarding income from foreign countries.

How Lanturn’s Corporate Tax Services Can Help

ECI & CI Filing Support

Lanturn provides expert support in preparing and filing both Estimated Chargeable Income (ECI) and Form C/C-S submissions. With in-depth knowledge of IRAS corporate tax rules, Lanturn ensures accurate and timely submissions that keep your business compliant.

Corporate Tax Planning Services

In addition to compliance, Lanturn offers GST registration, GST quarterly filing, dormant returns, and tax waiver planning strategies designed to optimise tax outcomes.

Tax planning activities include leveraging available exemptions, structuring cross-border transactions, and advising companies on the tax treatment of various business activities.

Lanturn’s primary goal is to reduce tax liabilities while ensuring compliance with Singapore’s tax framework.

Leave your tax filings with Lanturn’s team of experts. The company stays on top of your accounting and tax needs, and we make sure everything is filed on time with 100% accuracy.

Why Choose Lanturn for Your Corporate Tax Needs

Expertise with IRAS Regulations

Lanturn’s professionals are well-versed in the latest developments in corporate income tax in Singapore. From changes in ECI requirements to updates on exemptions, our team ensures your business always remains compliant with IRAS regulations.

Tech-Driven Tax Filing Solutions

Lanturn streamlines the tax filing process, offering transparency, efficiency, punctuality, and secure document management. This reduces manual errors and simplifies compliance for businesses of all sizes.

Tailored Services for Startups & SMEs

Lanturn specialises in corporate tax services in Singapore tailored to both startups and SMEs, and larger businesses alike. We understand the unique challenges faced by smaller businesses and provide scalable solutions that grow as your company expands. Reach out to us today and let us help you stay ahead of your tax deadlines.