Q. Can one give a cheque for Matanot Laevyonim or does it have to be cash?
A. Horav Shlomo Miller's Shlit'a opinion is that if the cheque is made in the name of the receiver or for cash, and the needy receiver can exchange it during Purim, one complies.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller, Horav Dovid Pam, Horav Aharon Miller and Horav Chanoch Ehrentreu Shlit'a