Employer contributions and social security contributions are taxes paid by an employer to the state.
These statutory contributions fund the social insurance system. Social insurance provides entitlement to forms of social protection such as pensions, sickness benefit and unemployment benefit. In Sweden, employers are required to pay these social security contributions for every employee.
As a self-employed contractor, you bear these costs yourself. They are deducted from your invoice amount excluding VAT. The percentage varies by age, but the standard rate is 31.42%.