First: If the question concerns the validity of the contract, the contract is valid if both parties agree to it before leaving the contract session. Lying does not affect the validity of the contract; it leads to sin, not invalidation of contracts. Contracts concern validity or invalidity, not sin or reward. This is similar to someone lying to their spouse about something to make them accept marriage; the lie is sinful, but the contract is valid as long as its pillars and conditions are met.
This is concerning the contract. As for the earnings resulting from the contract, it depends on the work. The condition for the permissibility of the earnings is fulfilling the required duties. If you do your agreed-upon work, your earnings are permissible. If you fall short due to your actions or lies, your earnings are only permissible to the extent of your good work.
Second: Regarding what you did in your resume, it requires detail:
If the adjustment you made is within what your qualifications and experience can reasonably support, it is permissible. For example, a lawyer who studied law comprehensively but mainly worked on compensation cases may apply for a position in contract cases or civil rights cases, which he can handle by virtue of his studies. Similarly, a high school teacher applying for a university teaching position, given the similarity between the jobs.
If the description fits this scenario, there is no issue. However, if the adjustment is beyond what your qualifications and experience can support, you have lied and been deceitful, and you must repent to God.
From your question, it appears you used ambiguous language. Ambiguity and puns have different rulings depending on the situation, the addressee, and the consequences. Using puns is not always permissible. The rule is as stated by Imām An-Nawawī, may Allāh have mercy on him: “Know that equivocation and puns mean using a word that appears to have a certain meaning, while intending another meaning that the word can also refer to, but which is contrary to its apparent meaning. This is a form of deception and allusion. Scholars have said that if a significant legitimate interest outweighing the deception of the addressee necessitates this, or if there is a need that cannot be met except through lying, then there is no harm in using ambiguity. If none of these conditions are present, it is disliked, but not forbidden, unless it is used to take something unjustly or deny a right, in which case it becomes forbidden. This is the rule.”
So, consider whether your ambiguity led to taking a right that you do not deserve or cannot fulfill. If so, it is forbidden and you are sinful, but the contract remains valid, and you must repent to Allāh. If this is not the case, there is no issue.
Fatwā issued by Dr. Khālid Naṣr