The Hungarian Helsinki Committee explains in a short animated video what challenges do prisoners face when wanting to lodge a complaint, what international standards say about it, and why it is important for National Preventive Mechanisms to place special attention on this issue. This video was produced as part of the EU funded Project "Improving judicial cooperation across the EU through harmonised detention standards - The role of National Preventive Mechanisms" by the Ludwig Boltzmann Institute of Fundamental Human Rights, the Associazione Antigone, the Bulgarian Helsinki Committee, the Hungarian Helsinki Committee.