A major trends in collective bargaining across Europe is decentralisation, involving a shift from multi-employer to single-employer bargaining. In this chapter, the authors address the question of how decentralisation affects the relationships between trade unions and works councils in dual channel systems of interest representation. The analysis focuses on Germany and the Netherlands, two countries with legally established dual-channel systems of employee representation, where trade unions and works councils play a role in both consulting and negotiating employment and working conditions at the company level. While similar statutory allocations and demarcations of powers between works councils and unions exist in both countries, company case studies reveal marked differences in how trade unions and works council cooperate in practice.