We present impedance conditions up to the second order of approximation for the time-harmonic eddy current problem with a thin conducting sheet. The conditions are derived asymptotically for vanishing sheet thickness ε where the skin depth is scaled like ε. The first order condition is the perfect electric conductor boundary condition. The second order condition turns out to be a generalized Poincaré-Steklov map between tangential components of the magnetic field and the electric field.