- Verdict: ⛔ Avoid!
In the flaming pile of HMD's "great" decisions to improve Nokia, one stands out more than others: They decided to follow the fresh "lock the bootloader" trend.
Why was this necessary? I don't know...
Well, anyway. Models released before early 2019 can request unlocking using Hikari Calyx's unofficial service hikaricalyx.com
And for some other models, Hikari Calyx has a repo with prototype ABLs. fih-firmware.hikaricalyx.com
Models 7.2, 8.3 and 5.3 can be unlocked offline, while others may require HMD Device Kit which is not public and requires a service account.
As for Windows Phones, most models have an unofficial method of unlocking, which is supported by most Nokia Lumias, except for the 620, 720, and 1320.
Windows Phone info by Ivy / Lost-Entrepreneur439.
Updated info provided by Hikari Calyx.
Authored by melontini.