With the advent of online banking, the question arises as to whether one may schedule an automated payment from his bank account on Shabbat. Would such a transaction constitute a violation of the Rabbinic prohibition of making a "Kinyan" (Transaction) on Shabbat? On one hand, the instructions were issued before Shabbat, but the actual transfer was conducted on Shabbat.
The precedent for this question is found in the responsa of Rabbi Akiva Eiger. He discusses a case in which a father gave the Kohen five Shekalim for the Misva of Pidyon HaBen, redeeming the first born, on Friday. However, the father stipulated that the Kohen would not assume ownership of the coins until Shabbat. Rabbi Akiva Eger (1761-1837) concluded that such a transaction, initiated on Friday and ending on Shabbat, is prohibited. One might draw the same conclusion in the case of scheduling a bank payment.
Nevertheless, the Poskim point out a significant difference between the cases. In the case of the bank, the transaction is not executed by a person; it is done by means of computer. The general principle in the Halachot of Shabbat states that a person is not responsible for Melacha performed by his utensils. For example, one is allowed to put wheat in a mill on Friday, knowing that it will be ground on Shabbat automatically by means of water or wind. Similarly, one may set an automatic sprinkler system to be activated on Shabbat, since it is only the tools which are working. Since computers are also utensils, they too may be set to perform transactions on Shabbat.
SUMMARY: It is permissible to schedule an automatic bank payment for Shabbat.