This free Japanese phone number checker shows whether a number is valid.
A Japanese phone number checker tells you whether a number is real, which means it follows Japan's numbering rules and is assigned. Enter a +81 number above and 1Lookup's free checker returns valid or invalid in seconds, with the line type and country, checked against Japan's numbering plan.
Pick the country, then enter the number without the country code.
Free & rate-limited. No signup required to try.
- Country code
- +81
- Mobile numbers
- 10 digits after +81, or 11 written at home
- Landlines
- 9 digits after +81, such as +81Â 3Â XXXXÂ XXXX
- Written at home
- 090-1234-5678
- Written for apps and SMS
- +819012345678
- Dialed from the US
- 011 81 90 1234 5678
A Japanese mobile number is +81 followed by 10 digits, and a landline has 9 digits.
Written with the country code
- +81Country code
- 9First digit
- 0 1234 56789 more digits
Written at home
- 0Replaces +81
- 9First digit
- 0 1234 56789 more digits
The +81 and the 0 do the same job, so a number is never written with both.
A Japanese phone number checker reads a number's format first and then checks it against Japan's numbering plan.
This is the path one check takes. A number can be written correctly and still not be assigned to anyone, so the format check alone is not the answer.
- You enter the numberType it the way it is written at home, such as 090-1234-5678, or paste it with +81.
- Its format is checkedEach type of number has its own rules. A mobile needs 10 digits after +81 and a landline needs 9 digits.
- It is checked against the numbering planNumbers outside the US and Canada are checked against the numbering plan of their country, which for this page is Japan's.Nothing is sent to the number, so it never rings and its owner is never told.
- You see valid or invalidWith the line type and country in a few seconds, and the carrier or network where one is listed.
A Japanese mobile number has 10 digits after +81 and a landline has 9 digits, so the length shows which one it is.
These lengths come from the numbering data for Japan. A mobile number has 11 digits when it is written at home with its 0. Mobile and landline numbers can start with the same digit, so the first digit alone does not give the type, and the length does.
| Number type | Digits after +81 | Written at home |
|---|---|---|
| Mobile | 10 | 090-1234-5678 |
| Landline | 9 | 03-XXXX-XXXX |
Three common mistakes make a Japanese number fail the check, and each one is quick to fix.
Keeping the 0 after +81 adds a digit.
The 0 is only for dialing inside Japan, so +81 090 1234 5678 is wrong. Drop the 0 and write +81 90 1234 5678.
Typing too few or too many digits makes a number invalid.
A mobile number has 10 digits after +81 and a landline has 9 digits. With fewer than 9 or more than 10 a number cannot be valid, so look for a missing or doubled digit.
Leaving the wrong country selected changes how the number is read.
The checker reads a number by the rules of the country selected above, so keep Japan selected for a +81 number. Paste a number with its + and country code and the country is read from the number itself.
These are the questions people ask most about checking Japanese phone numbers.
How do I check if a Japanese phone number is valid?
Enter the number in the box above with Japan selected. The free checker returns valid or invalid in seconds, with the line type and country. Type it the way it is written at home, such as 090-1234-5678, or in full as +81 90 1234 5678.
How many digits is a Japanese phone number?
A mobile number has 10 digits after +81, or 11 written at home. A landline has 9 digits after +81, such as +81 3 XXXX XXXX.
Can I tell a Japanese mobile number from a landline by its digits?
Not by the first digit alone, because mobile and landline numbers can start with the same digit. The length helps: a mobile has 10 digits after +81 and a landline has 9 digits. The line type in the result gives the type.
How do I write a Japanese number for an app or an SMS tool?
Use the E.164 form: a plus sign, 81, then the number without its leading 0 and no spaces, such as +819012345678.
Does the Japanese phone number checker show the carrier?
It shows the carrier or network where one is listed. Numbers outside the US and Canada are checked against the numbering plan of their country rather than live carrier data, so some come back with no carrier name.
Does valid mean the Japanese number is active?
No. Valid means the number is real, correctly written for Japan and assigned. Whether a line is switched on and reachable right now is a different question, and the free HLR lookup answers it.
Can I check a whole list of Japanese phone numbers?
Yes. This free tool checks one number at a time. A 7-day free trial opens CSV upload and the API, at 1 credit a number.
Does the person know I checked their number?
No. The check reads records only. No call or text goes to the number, so its owner is never told.
What are the landline area codes of Tokyo, Osaka and Yokohama?
At home the codes are 03 for Tokyo, 06 for Osaka and 045 for Yokohama. From abroad the 0 is dropped, so Tokyo is +81 3. The area code is part of a landline's digits, and a mobile number has none.
You can check numbers from other countries on their own pages.
- +61Australian phone number checker
- +1Canadian phone number checker
- +44UK phone number checker
- +353Irish phone number checker
- +91Indian phone number checker
- +65Singapore phone number checker
- +234Nigerian phone number checker
- +64New Zealand phone number checker
- +60Malaysian phone number checker
- +66Thai phone number checker
- +63Philippine phone number checker
- +27South African phone number checker
- +254Kenyan phone number checker
- +233Ghanaian phone number checker
- +971UAE phone number checker
- +92Pakistani phone number checker
- +880Bangladeshi phone number checker
- +94Sri Lankan phone number checker
- +852Hong Kong phone number checker
- +256Ugandan phone number checker
- +255Tanzanian phone number checker
- +260Zambian phone number checker
- +356Maltese phone number checker
- +357Cypriot phone number checker
- +31Dutch phone number checker
- +49German phone number checker
- +62Indonesian phone number checker
- +966Saudi phone number checker
- +251Ethiopian phone number checker
- +962Jordanian phone number checker
- +52Mexican phone number checker
- +55Brazilian phone number checker
- +34Spanish phone number checker
- +33French phone number checker
- +39Italian phone number checker
- +82South Korean phone number checker
- +84Vietnamese phone number checker
- +20Egyptian phone number checker
- +90Turkish phone number checker
- +972Israeli phone number checker
- +48Polish phone number checker
- +54Argentine phone number checker
- +57Colombian phone number checker
- +56Chilean phone number checker
- +51Peruvian phone number checker
- +32Belgian phone number checker
- +41Swiss phone number checker
- +46Swedish phone number checker
- +351Portuguese phone number checker
- +58Venezuelan phone number checker
- +593Ecuadorian phone number checker
- +502Guatemalan phone number checker
- +1Dominican phone number checker
- +591Bolivian phone number checker
- +598Uruguayan phone number checker
- +506Costa Rican phone number checker
- +507Panamanian phone number checker
These free tools answer the next question about a number.
- The +81 country code pageHow to dial Japan, the time there now and the landline places.
- HLR lookupCheck whether a mobile number is switched on and reachable right now.
- Line type lookupSee whether a number is a mobile, a landline or VoIP.
- Carrier lookupFind the carrier or network behind a number.
- Phone validator for any countryThe same check with the country picker open to every country.
- Phone validation APIRun the same check from your own software, one request per number.
Sources: Google's libphonenumber numbering data for lengths, mobile starts and landline starts, as of September 24, 2026; the ITU list of country codes.