The main basic telephone service in Japan is provided by NTT (Nippon Telephone and Telegraph Corporation), which used to be a public monopoly. Here are some useful numbers for contacting NTT. When selecting a telephone service, make sure that it is compatible with whatever internet service you wish to use.

• Installation, changes of address: 116
• Helpdesk for telephone malfunctions: 113
• English-speaking operator: 0120-364-463 (9 am–5 pm Mon–Fri)
• International operator: 0051
• Directory assistance (in Japanese): 104
• Collect calls (reverse-charge calls): 106

KDDI, SoftBank Telecom, and other companies have a wide range of money-saving services that can be used from NTT phones. For example, when you dial from a normal NTT phone to a mobile phone, you can use SoftBank Telecom and save money by using the 0088 prefix.

• KDDI inquiries: 0057 (24 hours, free), international operator: 0051
• SoftBank Telecom: 0088-41.