Since a simple IMEI-to-Code calculator does not exist for these versions, unlocking generally happens via these methods:

Huawei uses an algorithm to generate Network Control Keys (NCK)—commonly known as unlock codes—based on your phone's unique IMEI number. Over the years, Huawei changed its algorithm. This is where the versioning comes in:

Important Note: Huawei stopped supporting bootloader code unlocks via official channels in 2018. By 2020, carrier unlock code calculators stopped working for models released after mid-2018 (those with EMUI 8 or newer). If you have a Huawei P20, P30, or Mate 20, this method will not work.

DC-Unlocker still supports a very small number of older models (e.g., Huawei P9, Mate 8, Honor 8) with the v4 algorithm. You must purchase credits (typically €4 per unlock). However, for any device with Kirin 960 or newer, DC-Unlocker will show: "Unlock not available for this model."

Even if you have a v4 or v5 calculator, many Huawei devices require a server-side token from Huawei’s internal servers. Without that token, the generated code, even if mathematically correct, is rejected by the phone’s fastboot.