San Francisco cannot have an income tax. This is forbidden at the state level. (http://taxes.about.com/od/statetaxes/a/States-Prohibiting-City-Income-Taxes.htm

San Francisco cannot have an income tax. This is forbidden at the state level. (http://taxes.about.com/od/statetaxes/a/States-Prohibiting-City-Income-Taxes.htm http://taxes.about.com/od/statetaxes/a/States-Prohibiting-Ci...) San Francisco CAN have a payroll tax, levied on companies based on pay to employees, a sort of shadow income tax. And indeed it does have a payroll tax. But you'll notice Twitter, Zynga and various other tech companies have gotten themselves exempted (for new hires, after moving to certain downtrod locations, at least in Twitter's case). (There was a brief political battle between the left and unions like SEIU who opposed these tax breaks and a tech coalition involving Ed Lee, Ron Conway, Twitter and many others who support the payroll tax breaks. Obviously the latter group won.)