Corporate Tax Guide: Filing Form C-S/C

Staff Writer

January 18, 2022

What’s in the article?

In Singapore, Form C/C-S happens to be one of those tax forms that every business must get accustomed to. Otherwise, failing to file your company’s Form C/CS in time might compel the Inland Revenue Authority of Singapore (IRAS)  to prepare your corporate tax bill based on income estimations. 

And that’s not all. Your company could also attract hefty fines and tax penalties, which may ultimately hurt the business itself. 

Now, to help you avoid that, this article provides all the critical guidelines on Form C and Form C-S in Singapore. You get to learn what they’re all about, their qualification requirements, as well as how to file Form C/C-S with the IRAS. 

What is Form C?

Form C/C-S, as it turns out, is just a broad term that collectively refers to two types of tax income return forms - Form C and Form C-S. 

Form C is actually the bigger sibling of the two. It comes in the form of a 7-page document, which Singapore-registered companies are required to fill in to declare their actual tax chargeable income. 

Usually, all companies in Singapore begin their income tax filing with ECI submissions. These are intended to provide the Inland Revenue Authority of Singapore with estimates of the chargeable income - within three months of each company’s financial year-end. Then since tax payments at this stage are based on estimates, Form C and Form C-S are submitted at a much later date to set the record straight, using accurate income figures. 

In essence, Form C/C-S should be submitted by December 15th for e-filing, or November 30th for paper filing. 

And to be specific, the Form C variant is typically filled out by companies with annual revenue of more than S$5 million. It’s considered the principal tax form because, in addition to providing income details across seven pages, it’s normally accompanied by supporting documentation such as financial statements and tax computations. 

What is Form CS?

Form C-S, on the other hand, is more like the smaller sibling of Form C. Although it serves pretty much the same purpose as its elder sibling, it’s much lighter and simpler. 

The IRAS introduced this version to save smaller companies the trouble that comes with Form C. Instead of painstakingly filling out seven pages, Form C-S allows them to report everything in just three pages: They are subdivided into: 

  • Information from the financial accounts.
  • Information on tax adjustments.
  • A declaration statement of the company’s eligibility.

What’s more, they don’t have to attach their financial statements and other supporting documentation - unless requested to do so by the IRAS. You just need to fill in the form and then submit it directly to the IRAS. 

But, make no mistake about it. Form C-S doesn’t completely exempt your company from preparing financial statements and tax computation. Although you won’t necessarily be required to submit them along with the form, the IRAS still expects you to have them handy. You might be requested to submit them for further verification of the tax details.

What Companies Are Qualified To Fill Out Form C-S? 

While Form C is open to all businesses, Form C-S is exclusive to companies that meet the following conditions: 

  • They must have annual revenue of S$5 million or less. 
  • They must be incorporated in Singapore. 
  • Their income is taxed at the prevailing corporate tax rate of 17%. 
  • They should not be claiming either foreign tax credit, investment allowance, group relief, trade losses, capital allowances, or tax deducted at source in the assessment year. 

Form C-S (Lite)

Recently, the government of Singapore has made things even simpler. From Assessment Year 2020 onwards, companies have the option of skipping Form C  plus Form C-S, and instead, filling out what is now known as “Form C-S (Lite)”. 

Yes, that’s right. This version is much leaner than the original Form C-S, as it only comes with six essential fields. 

But, get this - Form C-S (Lite) is only open to companies that qualify for Form C-S and happen to have yearly revenue of S$200,000 or less. 

What Are the Documents You Need Before Filing a Form C-S/C?

When it comes to filing Form C-S/C, companies must have the following supporting documents in pdf format: 

  • Tax computation and supporting schedules. 
  • Revised tax computations for previous Years of Assessment (YAs).
  • Detailed profit and loss statement.
  • Audited or unaudited financial statement report, complete with the Director’s Report, as well as the Statement by Directors. 

Then companies that intend to raise claims should have the corresponding declaration forms. 

How to File Form C-S/C

Before you even begin filing Form C-S or Form C, you should ensure that you’re authorized as the company’s “Approver” via CorpPass. Alternatively, you can go ahead and hire a tax agent to do the filing on your behalf. 

Whichever the case, here’s the full procedure for filing Form C-S or Form C;

  • Go to IRAS’s portal on 
  • If you’re an Approver, proceed to the “Business Tax Matters” section, and then log in to the system using your CorpPass credentials. Tax Agents, on the other hand, should use the “Client Tax Matters” section. 
  • Then on your dashboard, go to “Corporate Tax” along the main menu, and select “File Form C-S/C”. 
  • Choose the year of Assessment, followed by the form type - either Form C or Form C-S. 
  • You can then go ahead and fill out the form you’ve selected, attach all the relevant documents, confirm the details, and then submit the filing to the IRAS. 
  • Upon successful filing, the system will immediately display an acknowledgment page.  

Getting Started on Your Form C-S/Form C

Tax filing is a delicate matter that requires utmost accuracy. As such, it’s always advisable to work closely with seasoned tax professionals in SIngapore like WealthBridge. Make sure to drop us a message today for all your Form C-S/Form C and tax filing inquiries!

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