HMRC have now withdrawn PAYE and NI concessions for students.
As of April 2013 students will be treated in the same way as all other employees for PAYE tax and National Insurance contributions purposes.
Whether or not you pay tax on your part-time job depends on how much you earn, not on the number of hours you work. Everyone receives a certain amount of income in each tax year on which no tax has to be paid. This is called the Personal Allowance (£11850 in 2018-2019). If your earnings from your part-time job are below this (£228 per week ) , then you do not have to pay tax on them. If your earnings are more than this, you will pay tax on the difference.
If you have paid tax and your total taxable income for the year doesn't go above your Personal Allowance, you can claim a refund. You can even do this during the tax year if your income is likely to remain below your Personal Allowance. If you think you have paid too much tax you should ask HMRC for a repayment claim form P50 (Opens new window).
*Please note you must have submitted a New Starter Checklist to Payroll to ensure that you are on a correct tax code.