Do my parent have to inform the council I am taking a gap year?

No, not in the UK - the government thankfully doesn't yet ask where and what every of it's citizens is up to upon reaching adulthood. And now that you're above 18, sadly that means that all the legal responsibilities will come through you now.

Thank you so much for your reply. Of I contact the council myself I will be more them happy to pay them the amount they ask all at once as long as my parents don't find out. My course finished in 10th August officially and the new one starts January 22. So thats 6 months of council tax I will be more then happy to give them all at once as long as my parents don't find out is there a way I could do this?
Thank you

Also if the council suddenly increases the council tax by how much will it increase.

Are you living with your parents?

Council Tax is fixed by the value of the property, not by who lives in the property. If your two parents live int he same property they will likely already be paying full Council Tax so you living at home will make no difference. If you live elsewhere, the only issue is that students aren't liable for Council Tax, but you personally will be for the period between your two courses. So if you stayed in a house with other students, you alone woudl be responsible for paying all the Council Tax for that property.

Thank you so much for your reply. Of I contact the council myself I will be more them happy to pay them the amount they ask all at once as long as my parents don't find out. My course finished in 10th August officially and the new one starts January 22. So thats 6 months of council tax I will be more then happy to give them all at once as long as my parents don't find out is there a way I could do this?
Thank you

Household income affects benefits so I'd leave it well alone while you figure out what you're doing longer term. Citizens advice can help but be careful the personal details you give. If you are paying taxes they may pick it up. If you are working do you have a local family members address you can use? This assumes you aren't in receipt of any benefits such as carers allowance. I would try and get some advice from citizens advice or a disability charity

I don't work at all and whilst I could claim carers allowence it will affect my single parents benefits so I don't want to take any risks with that. So no income no benefits just some maintenance left over. I don't want my parent to get in trouble with the law so I can't just leave it. My new course is full time and starts in January so returning to my studies is my long term plan. I could get an exception from the council because I will be caring for them 35 hours a week (that's the entire reason I applied for the January intake) should I contact the council and tell them everything.