What is the IUA?

The International Underwriting Association of London (IUA) is the representative body for companies in London providing international and wholesale insurance and reinsurance coverage.

Mission Statement

To secure an optimal trading environment for London insurance companies.


Transform business processes by driving a modernising agenda of digitisation and automation
The IUA is at the forefront of market modernisation initiatives, promoting the design and implementation of modern processes and electronic interfaces using ACORD data standards. From placing to claims and accounting and settlement, our objective is to enable a more efficient marketplace.

Deliver knowledge and expertise for innovative underwriting and claims handling
A comprehensive range of market groups is run by the IUA to support best practice throughout the insurance life cycle.   

Represent members on matters of public policy and regulation
Legislation, regulation and compliance obligations are continually changing. The IUA assists members by monitoring and responding as necessary to authorities both in the UK and internationally. 



The IUA was formed on 31 December 1998, through the merger of the London International Insurance and Reinsurance Market Association (LIRMA) and the Institute of London Underwriters (ILU). This union brought together the representative bodies for the marine and non-marine sectors of the London company insurance market.

The ILU's history in the marine, aviation and transport insurance markets dates back to 1884. Senior members of marine insurance companies had, since the 1850s, been meeting informally in the Jerusalem Coffee House and the Jamaica Wine Rooms near the Royal Exchange to discuss policy wordings and other matters of mutual interest. A proposal was made to establish a formal representative underwriting association in July 1882 and two years later the new ILU took up offices in the Royal Exchange Buildings.

LIRMA was formed in 1991 from the merger of previous insurance associations, established in the 1960s and 1970s, to support non-marine insurance business and reinsurance.

In 2019 the IUA celebrated 20 years of representing the London company market. More details, including a picture gallery of our anniversary event are available here.

The London Market

The 'London Market' is a distinct, separate part of the UK insurance and reinsurance industry, centred on the City of London. It comprises insurance and reinsurance companies, Lloyd's syndicates, P&I clubs, and brokers.

Whilst there is no watertight definition of the market, there is general agreement that the core of its activity is the conduct of internationally traded insurance and reinsurance business. This is mostly non-life (general) insurance and reinsurance, with an increasing emphasis on high-exposure risks. There is also, however, an amount of life reinsurance activity in London.

Despite the growth of other international centres, London retains its position as the world's leading international insurance and reinsurance market. There may be far fewer companies operating in the market than in the late 1980s, but their average size has increased, and so has the overall level of business.

The London Market's international character is reflected not only in the sources of its business but also in the nationalities of its participants and their ultimate owners. A majority of the companies underwriting in the London Market are foreign or foreign-owned. It is still the only centre in which all of the world's 20 largest insurance groups are represented.

Insurance in London began well over 400 years ago, and gained prominence in the 19th century, reflecting Britain's then dominant role in shipping and shipbuilding. As the British Empire expanded London developed into a dominant global financial centre. For most of this period, the marine insurance industry was dominated by Lloyd's, but a flourishing company sector also developed and later expanded to embrace emerging aviation and energy markets. By the 1980s, the company non-marine sector had also grown to match the Lloyd's market, boosted by an influx of overseas capital.

An important competitive strength of the London Market lies in the number, diversity and expertise of the insurers competing here. Brokers can find the capacity and expertise required for the underwriting of virtually any type of risk. Brokers control most of the business placed in the market. London is largely a subscription market where risks are shared. A key feature is the presence of highly skilled 'lead underwriters' whose judgements on premium rates to be charged for different risks are supported by other insurers in London and indeed other markets across the globe.

Another important attribute is geographical concentration with many insurers and intermediaries located in close vicinity within the City of London. Thus, brokers can know personally the strengths, specialities and reputations of the underwriters and the insurers with whom they deal, and readily tap the combined underwriting capacity for all sectors of the market. Similarly buyers can meet insurers, and market information is spread rapidly among all participants.

The London Market also contains an unrivaled pool of service providers, for example law firms, IT support and professional bodies such as the IUA, and a robust but effective regulatory environment. All of these attributes contribute to an enviable reputation for innovation and security.


Who can be a member of the IUA?
The IUA is a membership organisation for companies, not individuals. Member companies are fully authorised international wholesale insurance and reinsurance businesses operating in or through London. For more information on membership visit our Member Services page.

What is the London company market’s premium income?
The IUA publishes an annual London Company Market Statistics Report surveying premium income which can be downloaded from the news section of this website.

What is the difference between the IUA and Lloyd’s?
The IUA is an association representing companies operating in London, but outside of the Lloyd’s market. We do not have any regulatory authority over our members. Lloyd's is a marketplace comprised of a society of members, both corporate and individual, that accept insurance risks through their participation in competing syndicates. The Lloyd’s Franchise Board and Lloyd’s Council are responsible for commercially managing the Lloyd’s market.

What is the difference between the International Underwriting Association (IUA) and the Association of British Insurers (ABI)?

The IUA represents the company wholesale insurance and reinsurance market in London. The ABI’s focus is much more UK-centric, looking at life and pensions and retail and commercial products.