Is leaving overtime work, despite the need for it, considered for the sake of Allah in a case where some colleagues postpone their work until vacation days to earn an additional amount, in violation of company policy? And is this permissible (halal) or forbidden (haram)?

The questioner is correct in their ruling regarding the impermissibility of overtime work prohibited by the company, except in cases of necessity, which does not apply to their situation. Adherence to contracts and conditions is obligatory, as Allah the Almighty says: "O you who have believed, fulfill [all] contracts," and the Prophet, peace and blessings be upon him, said: "Muslims are bound by their conditions." The questioner has done well by abandoning this work for the sake of Allah, and Allah will compensate them with something better, as Allah the Almighty says: "And whoever fears Allah - He will make for him a way out And will provide for him from where he does not expect," and the Prophet, peace and blessings be upon him, said: "Indeed, you will not abandon anything out of fear of Allah - Exalted and Mighty is He - except that Allah will give you something better than it."