I know that some LA's are thinking about imposing fines.
In my own experience, at my younger 2's school, they are allowed 10 days off per year, providing you do not take them out when they have SAT's. We also have to obtain written permission prior.
My eldest daughter's high school is far stricter. They only allow term time absences in special circumstances, and would not allow her to be off unless it was for " wedding abroad"
If you wish to take children out of school during term time you must gain permission from the school. The school can say no and then you may get into bother, including being fined. This was reported back in 2004 so it is quite possibly in place in some areas right now
Like the above poster said, you can only remove them for school for any 10 days per year