Okla. Stat. tit. 6, § 6-1711
Engaging in trust business at branch locations permitted -
Certain business at representative trust offices prohibited -
Limitations on business at out-of-state offices.
A. A state trust institution may act as a fiduciary and engage
in a trust business at each trust office as permitted by this act
and at a branch.
B. A state trust institution may not act as a fiduciary but may
otherwise engage in a trust business at a representative trust
office as permitted by this act.
C. Notwithstanding the provisions of subsections A and B of
this section, a state bank or a state trust company may not engage
at an out-of-state office in any trust business not permitted for
such an office by the host state where the office is located to
trust institutions chartered by such state.