A Montana single-member LLC operating agreement is used to establish the internal structure—such as ownership, management, and meeting procedures—of a limited liability company owned by a sole proprietor. Although not required by law in Montana, implementing an operating agreement allows the owner to limit their personal exposure to the company’s liabilities and debts. In addition, the document lends an extra layer of credibility to potential investors or financial institutions. Because there is only one signatory on the agreement, it should be signed electronically with a timestamp or acknowledged by a notary public to prove its validity.