TY - JOUR TI - Barriers to free movement due to mismatches of cross border tax and social security instruments AU - Pennings, Frans TI - Barriers to free movement due to mismatches of cross border tax and social security instruments AB - The rules for coordinating tax and social security have important differences, and this may be disadvantageous for mobile workers, in particular for posted workers. In this article the differences are analysed and the effects of the rules are shown. The article concludes by giving some suggestions for solving the problems JEL:  K31 ASJC: 3309 VL - Volume 25 (2018) IS - Tom 25 Zeszyt 4 PY - 2018 SN - 1429-9585 C1 - 2544-4654 SP - 307 EP - 322 DO - 10.4467/25444654SPP.18.019.8947 UR - https://ejournals.eu/czasopismo/szppips/artykul/barriers-to-free-movement-due-to-mismatches-of-cross-border-tax-and-social-security-instruments KW - koordynacja KW - pracownicy mobilni KW - zabezpieczenie społeczne KW - podatki KW - prawo Unii Europejskiej ; coordination KW - mobile worker KW - social security KW - tax KW - EU law