Those last two/three months of tax are in ADDITION to the tax already being deducted monthly for the preceeding year. To be fair, it is not extra tax, just payment in full seeing that tax here is paid in arrears. If you plan to leave for good, the gov will ensure that you don't leave without paying all of your taxes. That's a big bite of cash when you depart. I have no problem with Sing's tax rate - I do find my rent more than doubling in a year a bit hard to swallow