What Aon plc told the SEC could break it.

Approximately 51.8% of Aon's consolidated revenue is non-U.S. (attributed by where services are performed), and with a significant portion of its business outside the U.S. (operations in 120+ countries), it faces adverse FX movements against the U.S. dollar that could materially affect financial results and cash flows.

“Approximately 51.8% of our consolidated revenue is non-U.S., attributed on the basis of where the services are performed, and where products are[ sold]”

Aon is subject across jurisdictions to pension, investment, securities and insurance laws and supervision; e.g., providing/managing general underwriting for an insurer requires adhering to that insurer's regulations, and Human Capital services are regulated directly or indirectly via regulated third parties — evolving rules affect how Aon serves clients.

“if we are providing or managing general underwriting services for an insurer, we may have to adhere to regulations affecting our insurer client. Services provided in our Human Capital segment are also the subject of ever-evolving government regulation, either because the services provided to our clients are regulated directly or because third parties upon whom we rely to provide services to clients are regulated”

Aon sponsors defined-benefit pension plans worldwide, with its most significant plans in the U.S., U.K., Netherlands and Canada representing ~86% of projected benefit obligations (now closed to new entrants and frozen for future salary/service where permitted) — obligations whose funded status is sensitive to discount rates and asset returns.

“for Aon's significant U.K., U.S., and other major pension plans, which are located in the Netherlands and Canada. These plans represent approximately 86 % of the Company's projected benefit obligations.”

Aon's results could be adversely affected by a failure to realize the expected benefits of its NFP acquisition (including anticipated revenue and growth synergies) in the expected timeframe or at all, alongside execution risk on its Accelerating Aon United Program cost-savings/growth initiatives.

“because of a failure to realize the expected benefits of the acquisition of NFP, (including anticipated revenue and growth synergies) in the expected timeframe, or at all.”