For self employed (sole traders, partnerships, and LLPs):
Income tax will be applied on the profits and gains of the business which is remitted twice a year.
Class 2 NIC is a flat rate paid for every week, including holiday periods regardless of how much you earn. You can apply for Small Earnings Exception (SEE) to be exempt from Class 2 NIC liability provided that your net profit is expected to be less than the SEE limit. You must complete application form CF10 which is available at the HMRC website.