in the US the IRS is pretty known for working with you - if you call theyll set up a payment plan or whatever. ive known a number of people that got mildly bur

in the US the IRS is pretty known for working with you - if you call theyll set up a payment plan or whatever. ive known a number of people that got mildly burned by taxes, nothing crazy just unexpected, but with bigger numbers it could have been bad. When you have ISO(incentivized stock options), one of the incentives is you dont pay tax until you sell, which sounds great. There's this other way of calculating taxes, AMT(alternative minimum tax) which does not respect ISO, and you pay whichever is bigger. normally people dont get near AMT amounts, so most people dont know it exists. So when you exercise you think theres no tax, but then you do your taxes and realize actually you owe tax on money you never received.