I have only worked for less than half a year in Singapore. Why is my income tax so high?

You may have been assessed as a non-tax resident, where the overall tax rate tends to be higher. You can check if you qualify to be a Singapore tax resident, and if you do, you may file an objection using the “Object to Assessment” e-Service at myTax Portal. Alternatively, you can email/post the completed Request for Tax Reassessment (DOC, 203KB) form to us. Your income tax balance must be settled by the due date regardless of any objection. Any credit balance that arises from the review of your assessment will be refunded within 30 days.

This information provided here is sourced from the IRAS website.