The trust document controls the procedure for replacing a trustee who has resigned. Your document may indeed allow a resigning trustee to appoint a successor, but it should also contain provisions stating how a successor trustee can assume the office if the resigning trustee does not appoint someone else.
A financial institution will want to see the current trustee's resignation and then paperwork showing that a successor has been appointed and has accepted the office of trustee. Notarization is not required per se, however, the trust document may state that it must be done. You will have to consult the document and follow it completely.
Please note that if the trust owns real estate, documents should be recorded at a Registry of Deeds to reflect the trustees resignation. Those documents will need to be notarized.
Consulting a trust attorney would be a good idea; he or she will help you with the technicalities.
First of all, there are usually very specific procedures for Trustees to follow if they wish to resign. They are inserted into a trust for exactly this reason. So, if the Trustee who quit did not follow the procedures outlined in the trust, he would still be the Trustee. He may also be liable (depending on the terms of the trust) for any damage which results.
Second, there may be another term in the trust which provides for the appointment of successor Trustees in case the current Trustee resigns without nominating.
If there is no such provision, then the Uniform Trust Code of MA (assuming it is an MA trust) will govern the procedure.
You should have an attorney review the trust immediately. S/he will be able to answer the above questions, aid you in finding a new Trustee, perhaps even serve as the new Trustee, and assist you in taking any necessary actions against the current Trustee.
You really need an attorney. Period! You are asking for legal advice on a trust document that we have not read. No attorney can give specific legal advice without looking at the document. There is no other way to solve your immediate problem otherwise.
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