Am I permitted to receive a commission for marketing land when it is sold, even if I have a share in it or if it belongs entirely to me?

If a person collaborates with others in buying and selling land and exerts effort in selling and marketing it, then he is permitted to take a customary fee (ujrat al-mithl) for this additional work, provided he agrees with the rest of the partners. However, if he is the sole owner of the land and wishes to take a brokerage fee for it, this is not permissible unless he informs the buyer that he is an intermediary and the seller is another person, while also stating the brokerage fee. This would be a lie and deception. The preferred approach is for him to inform the buyer that he is the owner and negotiate the land's price with him.