Would Non-Definition of Payment Invalidate a Contract?

Answered by Ustadh Salman Younas
Question: I recently undertook some work (about six hours) for an employer with the understanding that I would be paid for it. The time, the payment money and the service were all not properly defined before the work. After the work, the employer sent $150 to my bank account as payment. Does this money belong to me? Is it lawful for me to use it?
Answer: assalamu `alaykum
The non-definition of payment and work does not always invalidate a contract. In fact, non-definition generally entails the contract being corrupt (fasid) and not invalid (batil), which means that the money one earned from such work would be permissible. However, it would be necessary to rectify such a contract and to ensure that one does not engage in such a practice in the future. [Ibn Abidin, Hashiya; Maydani, Lubab]
The reason non-definition is considered to corrupt a contract is due to the fact that it creates dispute between the two transacting parties. The basis when it comes to transactions according to the Qur’an is that it be undertaken and carried out with the mutual consent of both parties, which is something that is negated when there is non-definition in a contract.
Wassalam
Salman
Checked & Approved by Shaykh Faraz Rabbani.