Who chooses the independent auditing firm?

A company chooses who their independent auditing firm will be.
Any and all businesses, companies and organizations have the right to hire any auditing firm that they are going to pay to perform annual or special audits. (If a third party is mandating and paying for the audit due to an acquisition, merger, or a court order, then the third party will hire and pay an auditing firm of their choice.)

The Word independent means the auditing firm can not be related to the entity it is auditing. The auditing firm can not audit itself, a subsidiary of itself, a brother/sister organization, or its parent company.

Also, there can not be any conflict of interest. An employee for the auditing firm can not be on the team who audits a business that employs one of his/her immediate family, partners, or an organization in which he/she or his/her immediate family or partners has a material financial interest in, or has any arrangements concerning prospective employment with.

If all of the above hold true, you have an independent auditing firm.