The cantons and their municipalities are responsible for the organisation and financing of primary schools. The municipalities are responsible for the establishment and maintenance of pre-schools. School attendance is compulsory and free of charge for all children. The vast majority of children attend public schools. In most cantons, the school starting age for the primary level is reached once the child turns 6. The primary level usually lasts 6 years. In the few cantons in which entrance to the lower secondary level occurs already in school year 5 or 6, the primary level lasts 4 or 5 years. The harmonisation of compulsory education (HarmoS) will standardise the school structures in the cantons which join the HarmoS Concordat.