Measurements of charm production in ep collisions at a centre of mass energy of root s = 318 GeV performed by the ZEUS and H1 experiments at HERA are presented. Final states containing D mesons are used to identify charm production. Measurements cover both the photoproduction (gamma p), i.e. Q(2) similar to 0, and deep inelastic scattering (DIS), i.e. large Q(2), kinematic regimes. Experimental results are compared to QCD predictions.