Is it permissible to buy ongoing charity coupons with the intention of performing an ongoing charity for deceased Muslims, and does the reward for this act reach the deceased?

Purchasing coupons for ongoing charity (sadaqah jariyah) with the intention that their reward be for all deceased Muslims is a good deed for which the doer will be recompensed. The reward of the charity reaches every deceased Muslim, and it is not a condition to specify the reward for a particular person. This is evidenced by the Prophet, peace and blessings be upon him, sacrificing on behalf of his entire Ummah.