What is the ruling on a Muslim receiving a pension from a non-Muslim state by forging documents that prove his service for the required number of years, in exchange for the forger receiving a lump sum from the pension funds?

What is understood from the question is that the brother worked for eight years and wants to pay a bribe to have his documents falsified to show that he worked for ten years. This is forgery and is not permissible. Therefore, he must either work the required period to be entitled to the money and rights, or refrain from forgery and deceit. Forgery is forbidden, based on the words of Allah Almighty: ﴿So shun the abomination of idols, and shun false speech.﴾ And based on the words of the Prophet, peace and blessings be upon him: "Shall I not inform you of the greatest of the great sins?" (He repeated it three times.) "Associating partners with Allah, disobedience to parents, and beware, false speech and false testimony." Falsehood (Al-Zoor) is lying and describing something contrary to its true nature. The fact that a Muslim country is affiliated with a non-Muslim country does not permit forgery. As for a person working as a policeman in his Muslim country, there is no harm in it as long as he does not directly commit anything unlawful or assist in it.