Japan's communications ministry has instructed the nation's mobile operators to give the option to unlock all new smartphones starting from next year.
The Ministry of Internal Affairs and Communications has issued a directive calling for all new smartphones sold from May 2015 to have their SIMs unlocked if asked by the customer, Reutersreported. The option must be offered at no extra cost.
While the ministry has been leaning on operators to offering a wider choice of data plans, they have held off on regulatory intervention until now.
The order is aimed at requiring incumbents NTT DoCoMo, KDDI and SoftBank to be more competitive with their pricing.
It is also expected to give MVNOs a chance to increase their market share from a combined 5%, by allowing them to woo customers from the incumbents.
Japan's MVNOs typically charge significantly lower prices for monthly plans, but the practice of locking customers to 24-month contracts has impeded adoption.
But analysts believe MVNOs' practice of not offering unlimited voice plans could be a hurdle to their growth ambitions.
If the order impacts the subsidies mobile operators offer on handsets, it could also potentially provoke a consumer backlash similar to the one seen in South Korea following the implementation of regulator KCC's new restrictions on handset subsidies.