All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
We have already issued Fatwa 82835 clarifying the conditions of attending the Friday prayer and we explained that a woman is not obliged to attend the Friday prayer.
The jurists determined that a person who is not obliged to attend the Friday prayer is exempted from the ruling that prohibits conducting contracts (like sale contracts and the like) when the second Athaan (i.e. the call for the prayer) is called. They conditioned the permissibility with the fact that the second party is not obliged to attend the Friday prayer. Therefore, if two persons who are not obliged to attend the Friday prayer conclude any contract, then it is not forbidden or disliked for them to do so, as explicitly stated by the scholars of the Shaafi'ee School of jurisprudence may Allaah have upon them.
However, if one party is obliged to attend the Friday prayer and the second party is not, then they are both sinful, as the first party who is obliged to attend committed a prohibition, and the second party who is not obliged to attend helped him in doing so; nonetheless, the contract they conduct is valid.
Moreover, the jurists of the Shaafi'ee School of jurisprudence stated that matters other than the sale contracts, due to which one may be preoccupied from attending the Friday prayer, take the same ruling as the sale contracts, as declared by Zakariyyah Al-Ansaari .
Allaah Knows best.