Codemasters' LMA Manager series was a short-lived rival to the likes of Championship Manager and Football Manager, and used a unique system for unlocking codes which allowed players to tinker with the gameplay.
A hotline was established in the UK that charged £1 per minute and provided special codes that could be used in the game to obtain unlimited money, faster healing for injuries, and more.
The catch? These weren't cheat codes you could freely share with other players – they were tied to your unique ID in the game, which meant they were totally unique to you. The only way to get them was to ring the aforementioned hotline.
Fast forward to the present day, and @bbayles has cracked the code across multiple versions of the game, allowing players to finally gain access to these bonus codes without having to reach for the phone (which, in 2026, is very useful, as the hotline has long since been disconnected).
The process differs for LMA Manager 2003-2005 and LMA Manager 2006; you can read about how the code was cracked here.
The LMA (League Managers Association) Manager series kicked off in 2001 and would stick around until 2008.