It sounds like some facts may be missing. A bank would not require an individual to open a trust checking account unless there was an existing trust. This trust was likely set up by a local attorney and they should be the one guiding you on how to handle the estate administration process and make certain everything is done according to the terms of the will and/or trust. Without reviewing those documents any guidance I might provide would be a mere guess.
That said, you should not be depositing an estate check to a trust checking account. If there is an open estate you will likely be filing an inventory and accounting with the Commissioner of Accounts, and thus all estate payments should be processed through the estate checking account. You should also have a tax identification number for the estate and a separate tax identification number for the trust (if it does in fact exist), and you'll also need to make certain all the appropriate tax filings are completed, including a 645 election, if your accountant deems appropriate.
If there is any confusion about this, or if you are unable to locate the attorney who drafted the documentation, please have your mother call me and I will gladly assist with this process.
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