You may use the 'Amend Tax Bill' digital service at myTax Portal to amend your tax bill for any of the following purposes:

1. Revise income declaration;
2. Add or amend claims for deductions and reliefs;
3. Claim Parenthood Tax Rebate; or
4. Change in tax residency status (non-resident to resident, if applicable).

This digital service allows you to easily view the pre-filled values in the original tax assessment and make amendments. Thereafter, you will be able to see a consolidated view of the revised income, deductions and reliefs and receive an instant acknowledgement upon submitting the amendment. We will issue the revised tax bill (digital/paper) or provide an update on the status of the amendment within 15 working days.

This information is sourced from IRAS