After the filing of Form C, if you wish to revise the amount declared in the Form C and/or submit revised tax computation, you can do so electronically via myTax Portal under “Object/Revise Assessment” if you have been authorised as an "Approver" for "Corporate tax matters" via EASY.
For more details on e-Service “Object/Revise Assessment”, please refer to:
User Guides:
For companies (340KB)
For tax agent (360KB)
FAQs (38KB)
Alternatively, you can write in to let us know your reason for making the revision, the item to be revised, the revised amount and attach revised tax computation where applicable.