In California, for instance: "A corporation may appear and participate in a small claims action only through a regular employee, or a duly appointed or elected officer or director, who is employed, appointed, or elected for purposes other than solely representing the corporation in small claims court." (CCP § 116.540)
If somebody's suing Mom and Pop's Corner Bakeshop, LLC, the corporation will probably be represented by Mom or Pop. If somebody's suing Coca Cola, the corporation will probably be represented by an in-house member of Coca Cola's legal division.
So a corporation can use a lawyer to handle its appearance in small claims court, but the lawyer has to be a regular employee. It's forbidden to hire a lawyer or firm specifically to litigate a case.
The person who represents Coca Cola may not be a licensed attorney, even if they work for the corporation. (See Code of Civ. Proc., § 116.530, subd. (a) and (b).) Corporations typically send a non-attorney member of their legal staff to appear for them.
Note that you cite CCP 116.540, but subdivision (m) specifically states:
(m) Nothing in this section shall operate or be construed to authorize an attorney to participate in a small claims action except as expressly provided in Section 116.530.
Thus, the the general rule of CCP 116.530 applies, despite the language you quote in CCP 116.540, subd. (b).
The controlling language in CCP 116.530 is:
(a) Except as permitted by this section, no attorney may take part in the conduct or defense of a small claims action.
(b) Subdivision (a) does not apply if the attorney is appearing to maintain or defend an action in any of the following capacities:
(1) By or against himself or herself.
(2) By or against a partnership in which he or she is a general partner and in which all the partners are attorneys.
(3) By or against a professional corporation of which he or she is an officer or director and of which all other officers and directors are attorneys.
(I serve as a temporary judge in CA and have presided over many small claims matters so I deal with this problem regularly.)
If somebody's suing Mom and Pop's Corner Bakeshop, LLC, the corporation will probably be represented by Mom or Pop. If somebody's suing Coca Cola, the corporation will probably be represented by an in-house member of Coca Cola's legal division.
So a corporation can use a lawyer to handle its appearance in small claims court, but the lawyer has to be a regular employee. It's forbidden to hire a lawyer or firm specifically to litigate a case.