noun
SIM unlock; SIM lock cancellation
Refers to the process of removing a carrier restriction so a phone can accept SIM cards from other providers.
海外旅行の前に、スマホのＳＩＭロック解除をしておいた。
Before my overseas trip, I had my smartphone's SIM lock removed.
この機種はＳＩＭロック解除が無料でできる。
This model can be SIM-unlocked for free.
SIMフリー describes a device that is already unlocked or sold without a carrier lock, while ＳＩＭロック解除 is the action or process of removing an existing lock.
Compound of English-derived シムロック (SIM lock) and 解除 (cancellation, release).