If the beneficiaries of the trusts/estates are all identifiable and you can obtain a statement (perhaps under oath, but not necessary in my view) that all beneficial owners are natural persons or otherwise eligible to hold NOW accounts directly, the estate/trust qualifies to hold a NOW account.
My experience tells me that it is a very rare case in which there would be a beneficiary that does not qualify to hold a NOW account directly.
I'll be discussing NOW account eligibility, among other things, on Wednesday, May 9, in a webinar, "Account Restrictions, Savings/MMDAs, CDs and Interest on Checking."
Check it out.