Using an estimated large-scale New-Keynesian model, we assess the consequences of introducing a fiscal union within EMU. We differentiate between three different scenarios: public revenue equalisation, tax harmonisation and a centralised fiscal authority. Our results indicate that no country would significantly benefit from introducing any form of fiscal union. Comparing long term, i.e. steady state, effects we have winners and losers depending on the scenario. Differences in terms of business cycle statistics as well as in terms of risk sharing of asymmetric shocks are minor. This also explains why welfare differences are small across the fiscal union scenarios. A counterfactual exercise indicates that with a fiscal union regime already installed at the start of EMU, key macroeconomic variables would have reacted very similarly while debt dynamics would have changed notably.