- you get 6M grace period to file by 15 Oct
- I simply filled up a simple form 4868 and handed it to the tax payer assistance center. Immediately accepted. Better keep the photocopy as proof
- beware you may get charged interest on shortfall (i.e. unpaid tax or negative refund) if you delay that payment. So it’s best to estimate the tax amount in advance.
- .. I think I was charged $11 interest on the ($1000+) shortfall because withholding tax was insufficient.