Hi, OMG I was thinking the same. I'm an A student and I think I may have scraped A* but if I get A or a mark off A*, I will be resitting it. I'm determined to get A* and I really have to. Anyway back to your question, I think it is allowed because my mum's manager has a daughter who got A in her maths but wanted A* so she re sat it. I think you have to let your teachers know from your current school but if you are moving schools for 6 form you have to let both schools know. Good luck! !!! Also i think you have to pay unless your teachers are determind that you will get the grade you want then they may pay