Frequently Asked Questions about Landline

A landline phone number consists of three parts: an area code, a local exchange code, and a subscriber number. The total is always 10 digits, but the length of each part varies by region.

• Tokyo (03): 2-digit area code + 4-digit exchange + 4-digit subscriber number
• Sapporo (011): 3-digit area code + 3-digit exchange + 4-digit subscriber number

In general, the shorter the area code, the higher the population in that region.

The first digit of the area code points to a broad region of Japan.

• 01: Hokkaido
• 02: Tohoku and northern Kanto
• 03: Tokyo
• 04: Southern Kanto and Koshinetsu
• 05: Tokai
• 06: Osaka
• 07: Kinki and Hokuriku
• 08: Chugoku and Shikoku
• 09: Kyushu and Okinawa

For finer-grained regions, see the area code pages on this site.

Several measures help reduce nuisance calls to a landline.

• Subscribe to caller ID and ignore unknown or withheld numbers.
• Use a phone with built-in nuisance-call protection.
• Sign up for NTT's nuisance-call rejection service.
• Look up unfamiliar numbers on this site to read user reports.

In households with elderly residents, phones that screen calls with an automated answer message are particularly effective.

Traditional landlines run over analog or ISDN copper lines, while fiber-optic phone services use IP networks delivered through fiber.

• Call quality: fiber-optic phones use digital transmission and tend to be more stable.
• Cost: fiber-optic phone plans usually have lower monthly fees and per-minute rates.
• Numbering: fiber-optic phones can keep the same area-code-based number.
• Power outages: fiber-optic phones go down during outages, while some traditional landlines keep working.

If you move within the same area-code region, you can often keep the same landline number, provided you meet a few conditions.

• The new address falls within the same area code and local exchange.
• The serving NTT exchange office does not change.
• For fiber-optic phones, the new address must be within the service area.

If you move to a different area code, you will need a new number. Always confirm with NTT in advance.