Here is how to get your KDDI Mobile account number and transfer PIN, and what to do with them when you move your number to another carrier.
Account Number
KDDI Mobile is an MVNO associated with H20 Wireless. They cater to Japanese-speaking customers and offer GSM SIM Cards for activation. Due to a language barrier and general lack of support, we were unable to obtain specific porting instructions. You can contact KDDI Mobile via the customer service line provided.
Transfer PIN
Ask KDDI Mobile for the transfer PIN. There is no default PIN — do not guess one.
KDDI Mobile Contact Info
Customer Service: 1-877-890-5001 | 1-888-533-4649
Hours: Monday – Friday: 9:00AM – 10:00PM (EST) | Saturday: 9:00AM – 6:00PM (EST) | Sunday: CLOSED
- Sales: 1-866-348-3370
- Tech Support: 1-877-520-0800
KDDI Mobile Porting Instructions
KDDI Mobile is an MVNO associated with H20 Wireless. They cater to Japanese-speaking customers and offer GSM SIM Cards for activation. Due to a language barrier and general lack of support, we were unable to obtain specific porting instructions. You can contact KDDI Mobile via the customer service line provided. KDDI Mobile does not publish porting instructions for US customers. Its US support line serves Japanese-speaking customers. The secondary number KDDI Mobile gives out redirects to H2O Wireless. KDDI America does not publish its US coverage details or porting instructions. Cannot find your carrier? Browse the full list of US carriers and MVNOs.
Check coverage before you port
We have not confirmed which national network KDDI Mobile uses, and we do not guess. Ask them before you port, then check that network’s map: Verizon, T-Mobile, AT&T.
Your right to keep the number is federal, not a carrier policy. The rule is the FCC’s: Portability: Keeping Your Phone Number When Changing Service Providers.
Working a counter? The KDDI Mobile transfer PIN lookup puts these steps on one screen and texts them to the customer.
Where KDDI Mobile customers usually go next
We have not independently confirmed which network KDDI Mobile uses, so check your IMEI against the new carrier’s compatible device list before you switch. Dial *#06# to get it.
T-MobileCheck your IMEI first
VerizonCheck your IMEI first
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Questions about KDDI Mobile
Can I keep my phone number when I leave KDDI Mobile?
Yes. Federal number portability rules let you take a working number to a new carrier. KDDI Mobile cannot refuse the transfer or charge you to release the number.
Should I cancel KDDI Mobile before I port my number out?
No. Cancel first and the number is released, which ends your right to move it. Keep the KDDI Mobile line active until the new carrier confirms the port completed.
How long does a port out from KDDI Mobile take?
A simple wireless transfer usually completes within one business day once the new carrier submits the correct KDDI Mobile account number and transfer PIN.
Does KDDI Mobile run on its own towers?
Not confirmed. KDDI Mobile has not published which host network carries its traffic.
Cite this page
Port-out details last confirmed with KDDI Mobile on 28 September 2026.
Best Cellular. “KDDI Mobile Account Number & PIN: Accurate 2026,” BestCellular.com. https://bestcellular.com/kddi-mobile/
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