Aon plc

   Cover Page Interactive Data File (formatted as inline XBRL).   * Certain exhibits and schedules have been omitted pursuant to Item 601(b)(2) of Regulation S-K. Aon hereby undertakes to furnish supplemental copies of any of the omitted exhibits and schedules upon request by the SEC; provided, however, that Aon may request confidential treatment pursuant to

Rule 24b-2 of the Securities Exchange Act of 1934, as amended, for any exhibits or schedules so furnished.   Safe Harbor Statement This communication contains certain statements related to future results, or states Aon’s intentions, beliefs and expectations or predictions for the future, all of which are forward-looking statements as that term is defined in the Private

Securities Litigation Reform Act of 1995. These forward-looking statements are subject to certain risks and uncertainties that could cause actual results to differ materially from either historical or anticipated results depending on a variety of factors. These forward-looking statements include information about possible or assumed future results of Aon’s operations. All statements, other

than statements of historical facts, that address activities, events or developments that Aon expects or anticipates may occur in the future, including, without limitation, statements about Aon’s outlook, expected market and industry conditions, including competitive and pricing trends, the development and performance of Aon’s services and products, the expected timing and closing

requirements for completing the proposed acquisition, the expected benefits of the proposed acquisition, including advances in the middle-market segment and access to the Excess & Surplus segment, business generation, revenue and

—         927        —         927   Earnouts receivable      —         —         474        474   Liabilities at fair value:             Acquisition earnout

obligations      —         —         (11,893 )       (11,893 )  Deferred compensation liabilities      —         (218,227 )       —         (218,227 )  Post-employment compensation liability

     —         —         (93,805 )       (93,805 )  Deferred compensation asset values are comprised of the cash surrender values related to underlying company-owned life insurance policies and mutual funds adjusted for market performance. Deferred compensation liabilities include obligations

related to the Company’s deferred compensation plan adjusted for market performance. The fair value is obtained based on observable market prices quoted in active markets for similar instruments. The employee loan receivables have a 5-year principal balloon payment and a floating market interest rate updated annually and their outstanding value approximates market value. The fair value of

acquisition earnout obligations is based on the present value of the expected future payments to be made to the sellers of businesses acquired in accordance with the respective agreements, which is a Level 3 fair value measurement. In determining fair value, the Company uses computations based on financial projections developed by management. The estimated future earnout payments are based on

the criteria and performance targets included in each purchase agreement. The earnout liabilities are discounted to present value using a risk-adjusted market rate of 10% for the six months ended June 30, 2026. Changes in the acquired financial projections, assumptions for revenue growth and/or profitability, or the risk-adjusted discount rate, would result in a change in the fair value of

recorded earnouts. The table below presents the changes in fair value for earnout liabilities categorized as Level 3:        Six Months Ended        June 30, 2026   Balance, beginning of period    $ 15,064   Net change recognized in earnings      955   Net additions      540  

    $ —         $ 61                                    (a) Represents reclassification of USI’s Net commissions and fees of $2,628 million, Contingents and supplementals of $262 million, and $26 million from Other income to Aon’s Total

revenue to conform to Aon’s historical presentation. Adjustments (b), (c), (d), and (e) reclassify $56 million from Other income to other accounts to align with Aon’s presentation. (b) Represents a reclassification of $26 million primarily relating to gains on deferred compensation assets from USI’s Other income to Aon’s Other income (expense) to conform to

Aon’s presentation. (c) Represents a reclassification of $2 million of sublease income from USI’s Other income to Aon’s Premises to conform to Aon’s presentation. (d) Represents a reclassification of $13 million primarily relating to gains on legal settlements from USI’s Other income to Aon’s Other general expense to conform to Aon’s

presentation.   Page 9 (e) Represents a reclassification of interest income earned on operating cash of $15 million from USI’s Other income to Aon’s Interest income to align with Aon’s presentation. (f) Represents reclassification of USI’s Stock-based compensation of $25 million to Aon’s Compensation and benefits to conform to Aon’s presentation.

(g) Represents a reclassification of $2 million of temporary labor expenses from USI’s Compensation and employee benefits to Aon’s Other general expense to align with Aon’s presentation. (h) Represents a reclassification of $73 million primarily relating to software maintenance and IT consulting expenditures from USI’s Other operating expenses to Aon’s

Information technology to align with Aon’s presentation. (i) Represents a reclassification of $57 million of lease expenditures from USI’s Other operating expenses to Aon’s Premises to conform to Aon’s presentation. (j) Represents reclassification of USI’s Acquisition-related retention and buydown bonuses of $10 million and Earnout adjustments and accretion

of discount of $4 million to Aon’s Other general expense to conform to Aon’s presentation. (k) Represents a reclassification of $6 million of acquisition-related tax obligations and settlements from USI’s Other non-operating income to Aon’s Other general expense to align with Aon’s presentation. The remaining balance of $42 million relates to a gain on

        Total          $ 37      $ 1,437      $ (8 )    $ 1,466                                            Earnout Obligations Certain acquisitions are structured with contingent purchase

price obligations commonly referred to as earnouts. At June 30, 2026, the total undiscounted earnout obligations ranged from $10,994 to $13,088 with a best estimate of $12,096. The discounted liability for earnout obligations on the Consolidated Balance Sheet totaled $11,893 at June 30, 2026. Acquisition-Related Costs Acquisition-related costs primarily consist of legal and due diligence

expenses and are included in Other operating expenses in the Consolidated Statement of Operations. The Company incurred acquisition-related costs of $246 for the six months ended June 30, 2026. Divestiture During the first quarter of 2026, we recognized a gain of $948 in Other non-operating income on the Consolidated Statement of Operations, related to earnouts on the sale of the international

      Goodwill changes arise from acquisitions, transfers between segments, and purchase accounting adjustments during the first twelve months following the acquisition date. The Company gave consideration as to whether events or changes in circumstances had occurred since December 31, 2025 that could indicate that the carrying amounts of the Company’s goodwill and other

intangible assets may not be recoverable as of June 30, 2026 and concluded that no such events or changes in circumstances had occurred to warrant a change in the assumptions utilized in the December 31, 2025 impairment tests of the Company’s goodwill and other intangible assets. The Company’s intangible assets by asset class were as follows: