Aon issues $13.5 billion of multi-tranche senior notes

Aon plc (NYSE: AON) issued $13.5 billion of senior notes on September 17, 2026, in seven series running from 2029 to 2056. Aon North America and Aon Global Holdings are the issuers. Aon plc, Aon Corporation and Aon Global Limited guarantee the notes. The disclosure is Form 8-K accession 0001193125-26-394533.

Seven coupons, one closing

Aon North America and Aon Global Holdings agreed on September 14, 2026 to sell the notes to underwriters represented by Citigroup Global Markets, BofA Securities, Morgan Stanley, Wells Fargo Securities and HSBC Securities (USA). The contract set delivery for 10:00 a.m. New York time on September 17, or as many as seven full business days later. The current report, signed that same September 17, treats the notes as issued. They sit under a second supplemental indenture of that date, on a base indenture dated March 1, 2024, with The Bank of New York Mellon Trust Company as trustee.

The series are $2.0 billion of 5.350% notes due September 17, 2029; $3.0 billion of 5.625% notes due September 17, 2031; $2.0 billion of 5.800% notes due September 17, 2033; $2.75 billion of 5.950% notes due September 17, 2036; $1.0 billion of 6.100% notes due September 17, 2038; $750 million of 6.450% notes due September 17, 2046; and $2.0 billion of 6.450% notes due September 17, 2056. Together those principal amounts are $13.5 billion. Interest on each series accrues from September 17, 2026 and is paid on March 17 and September 17, beginning March 17, 2027.

The notes are senior unsecured obligations of the two issuers. Aon plc, Aon Corporation and Aon Global Limited guarantee them fully and unconditionally, jointly and severally, on a senior unsecured basis.

What came in, and what the cash is for

Net proceeds were approximately $13,400,800,000 after underwriting discounts and estimated offering expenses. The prices the underwriters pay, in the underwriting agreement, start at 99.548% of principal on the 2029 notes and fall to 98.809% on the 2056 notes. The other five series sit between those two. The report does not break offering expenses out from the discounts.

The issuers intend the proceeds for general corporate purposes. Together with a term loan that Aon North America expects to enter, and cash on hand if it is needed, the money is also meant to pay the cash consideration for the previously announced acquisition of USI Advantage Corp., to repay certain debt of that company and its subsidiaries, and to pay related fees and premiums. This report gives no dollar figure for the cash consideration, the term loan, or any one of those uses.

The 101% call stops short of 2056

The report groups the 2029, 2031, 2033, 2036, 2038 and 2046 notes as USI Acquisition Notes. The 2056 notes are not in that group, even though they carry the same 6.450% coupon as the 2046 notes. If the acquisition is not completed by the earliest of June 1, 2027, a valid termination of the August 30, 2026 merger agreement, or a written determination by the issuers that it will not close, the issuers must redeem the USI Acquisition Notes at 101% of principal plus accrued interest. June 1, 2027 can be pushed out twice, by up to three months each time, if regulatory approvals are still outstanding.

Each series can also be redeemed at the issuers' option. Before its par-call date the price is a Treasury make-whole. On or after that date it is par, plus accrued interest. The make-whole spread is 10 basis points on the 2029 notes, 15 basis points on the 2031 and 2033 notes, and 20 basis points on the 2036, 2038, 2046 and 2056 notes.