Japan has a unique problem: the phone may be locked twice. There is the carrier SIM lock, and there is the "network lock" that Japanese handsets apply to eSIM and to some overseas SIMs even after release. Docomo, au (KDDI), SoftBank and Rakuten each run their own record, and the industry practice of selling devices on long instalment plans means a large share of second-hand Japanese stock is still locked.
The carrier holds an activation policy against the IMEI. Japanese iPhones are released by that policy; older Android handsets (Kyocera, Sharp, Fujitsu) may also use an unlock code entered after a specific key sequence.
Japanese law has shortened the mandatory lock period over the years (currently restrictions ease after 100 days of use for most carriers), but a device sold before that period is still locked.
The phone is not damaged and it is not stolen by default: the manufacturer holds an activation policy against the IMEI that names the carrier the device may activate on. Until that record changes, every other SIM is refused at activation — Wi-Fi keeps working, which is why a locked handset can look perfectly healthy in a shop.
Japanese carriers release devices on request once the instalment plan is complete or the mandatory period has passed, per MIC guidance. The request must come from the account holder.
Overseas use requires the device to be fully released; a "carrier-free" claim from a marketplace seller is not proof.
The current wording is always on the carrier’s page: MIC (Japan) — SIM lock policy.
Second-hand Japanese devices are the classic case: the carrier will not deal with the buyer and the instalment record may still be open. The Japanese tiers are split by carrier because the records are split.
| Service | Price | Covers |
|---|---|---|
| Japan Docomo | NTT Blacklist Check - iPhone & Generic | $0.04 | Apple · Docomo · Japan |
| Japan KDDI | AU | UQ Blacklist Check - iPhone & Generic | $0.04 | Apple · KDDI · Japan |
| Japan Softbank Status Check | $0.04 | SoftBank · Japan |
| Japan Softbank/AU/KDDI/UQ/Docomo Status Check Support Apple/Generic | $0.04 | Apple · Docomo · Japan |
| Japan KDDI | AU | UQ Unlock - iPhone 6s-12, Samsung, SONY & Generic | $0.50 | Apple · KDDI · Japan |
| Japan Docomo | NTT Unlock Clean & Under Contract - iPhone 6s-SE-12 Samsung, SONY & More | $0.57 | Apple · Docomo · Japan |
| Japan Softbank | Ymobile Unlock - iPhone iPhone 6s-SE-12, Samsung, SONY & More | $2.50 | Apple · SoftBank · Japan |
| Japan Docomo | NTT Unlock Blacklisted - iPhone 6s-SE-12 Series | $3.50 | Apple · Docomo · Japan |
| Japan Replacement Unlock Clean - iPhone | $7 | Apple · Japan |
9 services in this guide. Prices are live; sign in for volume pricing.
Long instalment plans and resale before completion.
Different record, different tier.
Some use keypad codes — see the code services.
Yes for record-based releases.
Yes — a $0.03 carrier check plus a blacklist check.
Last checked 2026-10-28. Carrier rules are summarised from the operators’ own pages; where a rule has changed since, the operator’s page wins.