Me again, coming back with a new question. Sorry for being so not organised. What is National Insurance contributions. Do we have to pay them, in what circumstances and when do we start to pay them?
I assume you are talking about UK. National Insurance Contribution are related to Social Securtity in the UK and paid by both employers and employees. It is about 5-10% of the salary for an employee. More information on the page UK - National Insurance Number