Aon has launched Sidecar X, a dedicated capacity platform offering up to $200 million for representations and warranties (R&W) and tax insurance as the transactional risk market faces higher rates, rising claims and increasingly complex deals.
The platform connects participating insurer and reinsurer capital with transactional risk placements through pre-agreed underwriting, pricing and claims frameworks. Aon said the structure is designed to shorten execution times while providing clients with a 10% premium discount compared with standard market terms.
Sidecar X is available exclusively to Aon clients across the US, Canada, UK, European Economic Area and Asia.
The platform covers R&W insurance, known as warranty and indemnity insurance in the UK and Europe, as well as tax insurance products.
Unlike traditional reinsurance sidecars, which are typically collateralized vehicles that allow investors to participate in a reinsurer’s underwriting risk, Sidecar X is a pre-committed capacity facility. Participating insurers and reinsurers agree in advance on underwriting parameters, claims protocols and pricing terms.
Aon said that structure is intended to reduce the bilateral negotiations that can slow transactional risk placements and give clients greater certainty when deals are moving on tight timelines.
Transactional risk market firms
The launch comes as pricing and claims activity in the R&W market have increased following several years of declining rates.
R&W rates in North America increased 16% year over year in 2025, according to Gallagher’s transactional risk data. Average quoted rates rose from 2.5% in the fourth quarter of 2024 to 3.23% in the fourth quarter of 2025.
Claims activity has also increased alongside transaction values. Aon’s 2026 Global M&A and Transaction Solutions Claims Study found that North American clients recovered more than $440 million through R&W claims in 2025, while median claim payments increased to $8.2 million from $5.5 million.
Global M&A deal values reached nearly $5 trillion in 2025, according to McKinsey, with the number of transactions valued above $10 billion reaching its highest level since the 2021 post-Covid peak.
That combination of larger transactions, rising claims and firmer pricing has increased the importance of capacity and execution certainty for brokers and clients placing transactional risk coverage.
Aon expands its transactional risk platform
Sidecar X builds on Aon’s existing Sidecar platform, which the broker said has supported transactional risk placements across its client base.
The company said Sidecar X gives participating insurers and reinsurers an analytics-led view of diversified transactional risk portfolios, helping them make underwriting decisions and deploy capital at scale.
Christian Hoffmann, CEO of commercial risk at Aon, said the platform is intended to provide clients with greater clarity as transaction risks become more complex.
Martyn Chattey, chief broking officer for the Americas, said Sidecar X is designed to connect capital with transactional risk portfolios in a more efficient way.
The move comes amid broader expansion in the transactional risk market. Arch Insurance North America launched a direct US transactional liability team in July focused on R&W and tax insurance, while DUAL introduced a unified global transactional risk practice backed by Liberty Specialty Markets.
For Aon, Sidecar X adds another layer of dedicated capacity to its transactional risk offering while attempting to make R&W and tax insurance placements faster and more predictable for clients.
