Officially 6 per year (from the time you joined etc). However, my consultant tends to be quite flexible with them and does allow you to have more - (but for good reasons, not just if you fancy having a week off, but if you have more holidays away booked, or if you have urgent childcare probs etc) Cant guarantee that other Cs would be so flexible though.
It's hard to be flexible on the new card system as it recognises your holidays/sick days etc. The only way to have more would be if your consultant overrides the payment and that depends on how much of a businesswoman she is!
I don't know how she gets round it to be honest, I know she occassionally gets head office to override things to sort it all out - and she certainly doesnt broadcast it as an option to people, just quitely sorts it out when necessary. I just asked her about it once, as I was worried that some people seemed to be using up all their holiday and I thought they were limited to 6 and she just said that she was happy to be flexible if people had genuine problems getting to class.
I dunno, maybe she is losing money!! She is very nice after all!