Is zakat obligatory on the deceased father's money, which is in a current bank account that yields no interest, and which you have been unable to transfer to your account?

Money becomes the property of the heirs immediately upon the father's death. Zakat (definition) is not obligatory on it unless the share of each heir reaches the nisab (definition) on its own, or when combined with other money of the same type that they possess. At that point, Zakat becomes obligatory. The heir may choose to pay Zakat at the end of the hawl (Zakat year) or delay it until they receive the money, then pay Zakat for the elapsed period, as long as they are unable to take possession of it. However, if they are able to take possession of it, Zakat becomes obligatory on them at the end of each hawl.