Pre-incorporation
Do I need to file a tax assessment even if I haven't started operating?
Yes, according to IRAS, not having started operations doesn't exempt a company from filing. What you actually need to file
Corporate tax return — A dormant company must file Form C-S/Form C-S (Lite)/Form C using the File Form for Dormant Company digital service on mytax.iras.gov.sg, unless it has been granted a filing waiver.
No financial statements needed — You need not submit your dormant company's financial statements to IRAS when filing as dormant.
How to get out of filing: the waiver
If you're likely to stay inactive, you can apply for a waiver so IRAS stops issuing you the return each year:
A newly incorporated company that has been dormant since incorporation and hasn't filed any Form C-S/Form C-S (Lite)/Form C can still apply for the waiver, as long as it's likely to remain dormant for at least the next 2 years.
Once granted from a specific date, the company won't be issued the form again from that date onward, no need to reapply yearly.
Per other guidance, qualifying conditions generally include not having earned any income and not owning investments that generate income.
If you later start operating
If a company is dormant but later recommences business or starts receiving income, it must inform IRAS, within one month of the date of commencement of business, by writing to IRAS with the company's UEN, date of recommencement, and other details.
Can pre-incorporation and pre-opening expenses be claimed, and is there a buffer period before the incorporation date for costs such as incorporation and accounting fees?
Expenses incurred before a business begins its income-producing activities are generally not tax deductible, since they relate to setting up the business rather than directly producing income. IRAS deems a company to have commenced business on the first day of the financial year in which it earns its first dollar of business receipt. Once that deemed commencement date is set, revenue expenses incurred from that date, as well as expenses incurred up to 1 year before it, become tax deductible. Do note that pre incorporation expense is not claimable for income tax purposes, unlike pre business commencement expense is claimable up to 1 year before earning the first dollar under the concession.
