Fatwa ID: 04218
Answered by: Maulana Belaal Ahmed
It states in Tashīl Al-Fiqh, V. 10 that "when the buyer has goods delivered to him and takes the goods on credit with the agreement that he will pay the seller the amount he (the seller) stipulates, then such a transaction is valid."
However, on the same page, it also states that in scenarios such as "the seller saying: take the item, I will not charge you extra", it is invalid.
بِسْمِ اللهِ الرَّحْمنِ الرَّحِيْم
In the name of Allah, the Most Gracious, the Most Merciful
Above are mentioned two scenarios regarding transactions, in the books of Fiqh transactions are mentioned in great detail and it is very important one learns about the issues in regards to them, because this is something one will do on a daily basis.
In regards to the question, the difference between the two is that in the first scenario the amount (value of the item) is fixed and clearly known and agreed upon therefore the transaction is valid whereas in the second situation the value of the item is (Majhool) unknown and a mutual agreement is not made on the amount, therefore, it not a proper transaction and may later lead to discrepancy hence the transaction is void.
Al- Hidayah kitaab ul buyoo vol 3 pg (Maktab Rahmaniya)
Fataawa Alamgheeri vol 4 pg 269 (Darul ishat print)
Only Allah knows best
Written by Maulana Belaal Ahmed
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham