| AON RISK SERVICES OF MISSOURI, INC. | 100183680 | 2000-04-10 | Merged | — |
| AON RISK SERVICES SOUTH, INC. | 100182641 | 2000-03-16 | Active | — |
| AON RISK SERVICES SOUTHWEST, INC. | 100104904 | 1993-06-08 | Active | — |
| AON RISK SERVICES, INC. OF ARKANSAS | 100008183 | 1985-07-10 | Merged | LITTLE ROCK |
| AON RISK SERVICES, INC. OF CENTRAL CALIFORNIA INSURANCE SERVICES | 100113785 | 1994-06-30 | Merged | — |
| AON RISK SERVICES, INC. OF COLORADO | 100155579 | 1998-02-02 | Merged | — |
| AON RISK SERVICES, INC. OF CONNECTICUT | 100143765 | 1997-01-31 | Merged | — |
| AON RISK SERVICES, INC. OF FLORIDA | 100158766 | 1998-05-04 | Active | — |
| AON RISK SERVICES, INC. OF FLORIDA | 100105881 | 1993-07-22 | Merged | — |
| AON RISK SERVICES, INC. OF GEORGIA | 100132558 | 1996-05-30 | Merged | — |
| AON RISK SERVICES, INC. OF GEORGIA | 100177988 | 1999-11-24 | Merged | — |
| AON RISK SERVICES, INC. OF ILLINOIS | 100094573 | 1992-02-05 | Merged | — |
| AON RISK SERVICES, INC. OF INDIANA | 100164516 | 1998-11-09 | Merged | — |
| AON RISK SERVICES, INC. OF KANSAS | 100177993 | 1999-11-24 | Merged | — |
| AON RISK SERVICES, INC. OF KANSAS | 100104865 | 1993-06-07 | Merged | — |
| AON RISK SERVICES, INC. OF KENTUCKY | 100178579 | 1999-12-13 | Merged | — |
| AON RISK SERVICES, INC. OF LOUISIANA | 100083289 | 1990-04-13 | Merged | — |
| AON RISK SERVICES, INC. OF MARYLAND | 100122578 | 1995-06-05 | Active | — |
| AON RISK SERVICES, INC. OF MASSACHUSETTS | 100171965 | 1999-06-09 | Merged | — |
| AON RISK SERVICES, INC. OF MICHIGAN | 100187392 | 2000-07-11 | Merged | — |
| AON RISK SERVICES, INC. OF MINNESOTA | 100178243 | 1999-12-03 | Merged | — |
| AON RISK SERVICES, INC. OF NEBRASKA | 100178362 | 1999-12-07 | Merged | — |
| AON RISK SERVICES, INC. OF NEW JERSEY | 100195773 | 2001-02-22 | Merged | — |
| AON RISK SERVICES, INC. OF NEW MEXICO | 100175753 | 1999-09-23 | Merged | — |
| AON RISK SERVICES, INC. OF NEW YORK | 100085687 | 1990-09-05 | Merged | — |
| AON RISK SERVICES, INC. OF OHIO | 100184245 | 2000-04-24 | Merged | — |
| AON RISK SERVICES, INC. OF OKLAHOMA | 100108914 | 1993-12-21 | Merged | — |
| AON RISK SERVICES, INC. OF OREGON | 100129908 | 1996-02-28 | Merged | — |
| AON RISK SERVICES, INC. OF OREGON | 100178011 | 1999-11-29 | Merged | — |
| AON RISK SERVICES, INC. OF PENNSYLVANIA | 100108805 | 1993-12-16 | Merged | — |
| AON RISK SERVICES, INC. OF PENNSYLVANIA | 100178007 | 1999-11-24 | Merged | — |
| AON RISK SERVICES, INC. OF SOUTHERN CALIFORNIA INSURANCE SERVICES | 100143270 | 1997-01-17 | Merged | — |
| AON RISK SERVICES, INC. OF TENNESSEE | 100114128 | 1994-07-15 | Merged | — |
| AON RISK SERVICES, INC. OF UTAH | 100113877 | 1994-07-06 | Merged | — |
| AON RISK SERVICES, INC. OF VIRGINIA | 800070448 | 2005-10-28 | Merged | — |
| AON RISK SERVICES, INC. OF WASHINGTON | 100113761 | 1994-06-29 | Merged | — |
| AON RISK SERVICES, INC. OF WASHINGTON, D.C. | 100183146 | 2000-03-28 | Active | — |
| AON RISK SERVICES, INC. OF WASHINGTON, D.C. | 100112339 | 1994-05-02 | Merged | — |
| AON RISK SERVICES, INC. OF WISCONSIN | 100177987 | 1999-11-24 | Merged | — |
| AON SELECT, INC. | 100135362 | 1996-09-04 | Merged | — |
| AON SERVICE CORPORATION | 100165313 | 1998-12-09 | Active | — |
| AON TECHNICAL INSURANCE SERVICES, INC. | 100134100 | 1996-07-23 | Merged | — |
| AON/ALBERT G. RUBEN INSURANCE SERVICES, INC. | 100114075 | 1994-07-14 | Active | — |
| AOP CLEANING SERVICES LLC | 811483899 | 2024-03-11 | Active | — |
| AOP HOLDINGS, LLC | 811274471 | 2020-11-12 | Active | — |
| AOP METAL FABRICATORS, LLC. | 811504708 | 2024-07-18 | Active | — |
| AOPA INSURANCE AGENCY, INC. | 100104155 | 1993-05-04 | Withdrawn | — |
| AOR MANAGEMENT COMPANY OF MISSOURI, INC. | 100213943 | 2002-06-03 | Merged | — |
| AOR MANAGEMENT COMPANY OF MISSOURI, LLC | 800158648 | 2002-06-03 | Active | — |
| AOR WORLDWIDE LTD. CO. | 800173828 | 2010-03-11 | Revoked | — |