Sept 23 student loan changes. Freshers only or all students?

[Fordian]

Sorry for the Americanism! But I gather that as of 2023, apart from the interest rate changing, the repayment period goes to 40 years, from 30.

DS2 goes into his final year then. Does his entire debt go to 40 years/ higher interest, or just the year's debt he accrues 2023/24?

Only those starting their course / taking out the first loan from.

Differences here

Thanks!