Frequently Asked Questions about IP Phone

An 050 IP phone is a phone service that routes calls over an internet connection (an IP network).

• Numbering format: 050 + 4-digit carrier code + 4-digit subscriber number, totaling 11 digits.
• Providers: NTT Communications, Rakuten Communications, KDDI, and others.
• Devices: dedicated adapters, smartphone apps, and softphone clients.

Unlike landline area codes, 050 numbers are not tied to any geographical region.

IP phone call quality depends on the quality of the underlying internet connection.

• Stable connections such as fiber: roughly comparable to a traditional landline.
• Mobile networks or congested links: latency and dropouts can occur.
• Quality tiers: the Ministry of Internal Affairs and Communications classifies IP phone quality from Class A (landline-equivalent) down to Class C.

By the 2020s, improvements in broadband quality have let many IP phone services deliver consistently stable calls.

IP phone calling rates are generally lower than landline rates. The figures below are rough guidelines as of 2026 and vary by carrier.

• IP phone to IP phone: often free within the same carrier.
• Calls to landlines: about 8 yen per 3 minutes nationwide.
• Calls to mobile phones: about 16 yen per minute.
• Monthly base fee: around 300 yen.

Note that some services do not support emergency calls such as 110 (police) or 119 (fire and ambulance), so check before relying on them.

050 numbers can come from many sources.

• Corporate call centers and customer support lines.
• Online stores or service providers contacting customers.
• Individuals using IP phone apps.
• Sales or telemarketing calls.

Because 050 numbers are easy to obtain, they are also used for nuisance calls. If you receive a suspicious call, look up the number on this site and check user reports first.

IP phones with 050 numbers generally cannot reach emergency services such as 110 (police) or 119 (fire and ambulance), because the carrier cannot reliably convey the caller's location.

As a precaution, prepare alternative options.

• Keep a mobile phone or landline available for emergencies.
• Note the regular phone numbers of your local police and fire stations.
• Fiber-optic phones with traditional 0AB-J area-code numbers do support emergency calls.

Both run over IP networks, but they differ in the numbers they use and the required service level.

• Hikari Denwa: a phone service provided by NTT East and NTT West over fiber-optic lines. It uses conventional area-code (0AB-J) numbers such as 03 or 06, must meet landline-grade call quality standards, and supports emergency calls such as 110 and 119.
• 050 IP phones: use 050 numbers that are not tied to any region and are easy to sign up for, even with just a smartphone app. Emergency calls are generally not supported.

This means a call from an area-code number is not necessarily from an analog landline; it may come from a fiber-optic (0AB-J) IP phone such as Hikari Denwa.

Unlike area codes, 050 numbers are not tied to any region, so you cannot determine where a call comes from by the number alone.

However, the four digits after 050 identify the carrier, so you can at least confirm which provider issued the number from the numbering assignments published by the Ministry of Internal Affairs and Communications. Subscribers' names and addresses are never published.

To learn more about who is actually calling, search the number on this site and check reports from other users.

If you do not recognize an 050 number, we recommend not calling back right away. 050 numbers are easy to obtain and are used both by legitimate corporate call centers and by sales, solicitation, and scam callers.

• Search the number first and check whether there are user reports.
• Confirm whether the company name or purpose is familiar to you.
• Calling back blindly can lead to paid voice guidance or attempts to extract personal information.

Calling back costs the same as any normal outgoing call; simply receiving the call incurs no charge.