In the United States and Europe, mobile phone subscribers are usually free to use the mobile phone or smartphone handset of their choice for voice and data communications by switching SIM cards.
But in In Japan, mobile carriers put SIM locks on their most popular handsets and offer sizable discounts on them to lure new subscribers.
The SIM lock removal could help bring down telecommunications fees. It is also seen as a way to promote the use of mobile virtual network operators, which offer cheaper services by using leased networks.
The Japanese ministry initially started plans for removing SIM locks in 2010, but little progress was made toward a full removal. Instead, carriers were under no obligation to remove them.