As a result of this shortage, the country plans to assign 10 billion 14-digit numbers before the end of 2021. The Ministry of Communications in Japan aims to draw up a report on the issue next month.
The plan to introduce new 14-digit numbers has already been accepted by three of Japan's largest mobile operators – NTT Docomo, KDDI, and SoftBank.
Japan currently uses 11-digit numbers starting with 090, 080, and 070 for mobile phones, while IoT devices in Japan use the 020 range.
Around 32.6 million of Japan's 80 million allocated IoT numbers have already been used up since January 2017.
IoT devices could be a significant contributor towards phone number shortages in other countries, as the number of IoT devices in the world continues to grow.
The IoT industry is expected to grow to a value of $581 billion by 2020, while active IoT devices have already surpassed the number of smartphones being used worldwide.