Is working in the business of selling telecommunication lines and exchanging them using another person's identity - which is against company regulations - unlawful (haram), and is the earning derived from it unlawful (haram)?

An employee must fulfill the terms of their employment and adhere to the permissible regulations of the company. This includes preventing the sale of SIM cards to an individual using another person's identity, even if they are a relative. Violating this could lead to harm for the identity owner. The employee is a private contractor who must abide by the terms of the contract, and their wages are not permissible to them unless they complete the agreed-upon work.