Student loan on rent-a-room over allowance

Hello, I was hoping to get some clarity on if/when student loan repayments are due on income from the rent-a-room scheme. I understand that if you are below the £7,500 tax free allowance that this is unregistered income and therefore student loan repayments are not due. However, if you are above this allowance, say £10,000 a year, will you be liable to pay student loan contributions on the whole £10,000 or just the amount over the £7,500 allowance i.e. student loan contributions woudl be due against the £2,500 part above this allowance?

Hi

It will just be the £2500 as this is the taxabale income.

Thank you