As in the UK, the process of gaining access to health care, unemployment payments, state pension and other benefits, begins by having a Social Security number (In the UK a National Insurance number). This enables you to work legally and to be protected by certain rights. It means that whether in employment through a company or working for yourself (Autónomo) you will be paying contributions.
Who has to pay Social Security in Spain?
Anyone living and working in Spain must register with the Social Security system and make these contributions in order to gain access to benefits. This may be through being employed by a company (so deducted at source from your salary), or by being self-employed (Autónomo) and making their own contributions into a state scheme specifically for the self-employed.
The overall rate for social security in Spain contributions is high in Spain compared to the UK, but the benefits are also more generous. For example, compared to the UK, the Spanish system rewards pensioners who’ve paid in more to a much greater extent. So if you make higher contributions over the years, on retirement you will gain a higher pension, unlike the UK, that has a flat rate.Of course if you are employed,the employer pays the majority of the cost.