We have a business account in which the sole owner passed away. It is an LTD business account type, with an EIN. In order to close the account, as the deceased's wife would like to do, what documentation do we need in order to process such a request? Do they need a court appointed personal representative specific to the business?

"LTD" does not have a nationwide usage in the U.S. In Europe it designates what we would call a corporation.

Assuming it is a corporation, then it is a shareholder who died, not the corporation. The issue is who owns the stock in the company. Assuming that the stock belongs to the decedent's estate, the court appointed personal representative could re-establish the management structure and take the steps necessary to wind down or dissolve the corporation.

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