As the Eurozone crisis lingers on, euro exit is now being debated in ‘core’ as well as ‘periphery’ countries. This column examines the potential costs of euro exit, using France as an example. The authors estimate that 30% of private marketable debt would be redenominated, but since only 36% of revenues would be redenominated, the aggregate currency mismatch is relatively modest. However, the immediate financial cost of exiting the euro would nevertheless be substantial if public authorities were to bail out systemic and highly exposed companies.