The prospects to test the hypothesis of intrinsic charm quarks in the proton are investigated. We consider how this component can be directly or indirectly probed in deep inelastic scattering at HERA and in fixed target experiments and find that an overlooked signal might be present in existing NMC data. Applying the intrinsic charm model to hadron collisions we compare the resulting charm production cross-sections with those based on standard perturbative QCD and available data. Extrapolating to higher energies we obtain predictions for charm production at the Tevatron and LHC.