If you give up work or are unemployed for a period of time you may be entitled to a tax refund for the particular tax year involved. This will depend on what other earnings you may have after ceasing work, e.g. social welfare benefits. You do not have to wait until after the end of the tax year to claim a refund. This can be done on an ongoing basis during the tax year by contacting your tax office.
People who work on a temporary basis e.g. students doing summer work may be entitled to a tax refund after they cease work. This refund can be claimed through your tax office. You will require a form P45 which your employer should have given to you when you ceased work. You send this to your tax office and they will deal with your refund claim.