Student Loan Repayments
HMRC then inform the Student Loan Company of the repayments you have made.
The repayment amount depends on your Plan.
For Self Employed health practitioners, Student Loan repayments are part their UK Tax Return.
Tax Payments On Account
Student Loan repayments are not calculated as part of Tax Payments On Account.
This means that any Student Loan repayment is to be paid through the Self Assessment Tax Return system by 31st January each year, based on the Self Employment profits for the previous tax year ended 5th April.
This is a link to the Student Loan Company (SLC):
Repaying your student loan
The document contains several references to Self Assessment and being Self Employed, particularly page 7.