Ruling on transactions made via modern means of communication

According to shareeah, a transaction is made when there is an
offer [of goods or services] and this is accepted, within the framework of shar’i
conditions and in the absence of anything that might invalidate the transaction. An
example of this in the case of a sale might be when the vendor says I sell this to
you and the purchaser says I agree. There have been major developments
in the field of communications which are now widely used to speed up financial dealings
and transactions, which we must bear in mind whilst also taking into account what the
fuqahaa have said about carrying out transactions via letter, in writing, by means
of gestures or through intermediaries. They also established that transactions should be
carried out between two parties who are present in the same place with the
exception of wills, the appointment of executors and the giving of power of attorney; the
offer and agreement should both refer to the same thing and price, there should be no
expression or indication that either party is turning away from the deal, and the
agreement to an offer should not be delayed beyond whatever timespan is customarily
regarded as acceptable.

In the light of the above, the fuqahaa have established the
following:

1. If the transaction is carried out between two parties who are not
   present in the same place where one can actually see the other or hear his voice, and the
   only means of communication between them is by writing, mail, sending a messenger, this
   applies also to telegraphs, telexes, faxes and computer screens, in these cases the
   transaction is complete when the offer reaches the prospective purchaser and he agrees to
   it.

2. If the transaction is drawn up at the same time, between two parties who
   are in different locations which applies to telephones and wireless communications
   the contract between them is considered to be a contract drawn up between two
   parties who are present in the same place, and in this case the basic rulings as stated by
   the fuqahaa and referred to in al-Deebaajah apply.

3. If the vendor makes a limited-time offer through these means of
   communication, he is bound by it for the duration and he cannot go back on it.

4. The rules outlined above do not include nikaah (marriage contracts)
   because of the requirement of two witnesses in nikaah, or barter because there has to be
   an actual exchange of goods or services, or forward buying, because this requires a cash
   down-payment.

5. In cases where there is the possibility of forgery, fraud or error,
   reference should be made to the general rules concerning the establishment of proof.l

And Allaah knows best.