IMO's autonomous ship code, the MASS Code, is in force: a two-year experience phase begins

The long-discussed framework for maritime autonomy has become official: the Maritime Autonomous Surface Ships (MASS) Code, adopted by IMO’s Maritime Safety Committee (MSC) in May 2026 under resolution MSC.595(111), entered into force on 1 July 2026 as a voluntary (non-binding) instrument.

The code establishes a goal-based framework for designing, building, operating and certifying remotely-operated or autonomous commercial ships to standards of safety and environmental protection equivalent to conventional ships. Its scope covers cargo ships subject to SOLAS Chapter I (generally above 500 GT, on international voyages).

Entry into force begins what IMO calls the Experience Building Phase. The formal framework for this phase will be developed at MSC 112 in December 2026 and will run for at least two years, during which member states will test the code in practice before it becomes mandatory under SOLAS. Development of the mandatory MASS Code is targeted for 2028, adoption for around 1 July 2030, and entry into force for 1 January 2032.

Apeks view — The headline reads like “autonomous ships have arrived,” but that isn’t the real story. The next two years are less about autonomy and more about data: the code puts the gathering of experience and records at the centre of the voluntary phase, and those records will shape the mandatory framework that follows. So even if you have no autonomy plan today, the message is the same: keeping your vessel’s sensor data, condition and the evidence for both in an auditable form is no longer a forward-looking choice, but a discipline where the early mover has the advantage. This is the quiet core of maritime technology: a sensor-based ship can only be managed if it has a readable memory.