Inland Revenue Authority of Singapore (IRAS) website contains some useful information.
They say filling of tax lands mostly on April. This year (2008) for tax filling for the year 2007 the due date is April 15.
Some say it's very easy to file your tax here since you can do it online. If you are eligible to file IRAS will send you a letter or your company/agency will send you the FORM IR8A which will contain the salary they have given you in 2007 to remind you that you need to file.
Now i got this from their website when i was asking myself "Who is eligible to file?". Browsing to their website i found out my category which is Individuals (For foreigners) > If you work in Singapore > If you are in Singapore for less than 183
days. (URL: http://www.iras.gov.sg/irasHome/page01.aspx?id=88)
Do I have to file tax? (URL: http://www.iras.gov.sg/irasHome/page.aspx?id=288)
You will need to file if you have received a paper form (Form B1/B/M) or a letter from IRAS inviting you to e-File.
Did not receive anything?
Even if you have not received any notification from IRAS to e-File, you need to file if:
=>your income for the previous year is $22,000 or more; and/or
=>you wish to claim tax deducted at source in respect of Singapore dividends that you received last year.
Please log in to myTax Portal to e-File your tax return by 15 Apr if you have not received any notification to file your return by 15 Mar.
If you are a new taxpayer who has not submitted any income tax form in the past, and you have not received any notification from us by 15 Mar , please complete and submit the registration form for new taxpayer (43KB) . We will activate your tax
account and send the paper form to you.
Tips to Avoid Penalty Being Imposed (URL: http://www.iras.gov.sg/irasHome/page03.aspx?id=116)
Income Less Than $22,000
Where an IRAS PIN Mailer / SingPass invitation letter / Income Tax Return has been issued to you, even if you are not liable to tax, you must file by the filing due date. If you have no income, you should declare ‘0’ in the respective income sections of the e-Filing template or Income Tax Return.
I also tried to call their helpline and had a pleasant experience. The "call agent" was very helpful and knowledgeable. For more details, other inquiries or confirmations call 6123-0000 if you're already in Singapore.
It wouldn't hurt to apply for Singpass ID in advance since it's very easy. Just make sure you have your Passport and EPASS Card if you're an EPASS holder or your SPASS card only if your an SPASS holder. The reason for this is because for EPASS
holders the Date of Issue is indicated in the Passport and not in the card. However in SPASS Card it's already indicated there. After the application you will receive your Singpass ID via Mail within 4 working days. You will use this ID for IRAS
transactions which e-filling tax is one of them. For more details go to https://www.singpass.gov.sg/sppubsvc/index.html.