IAG was founded in 1989 by 9 law firms across based Western Europe. They recognised the increasing need for reliably high-quality international resources to meet the increasing cross-border requirements of their clients. The group was always intended to include complementary professional disciplines, as its original full name, Integrated Advisory Group, implies, and IAG has always included an important minority of accountants and tax advisers.
IAG has always been, and remains, highly selective in admitting new members: this, and keeping overall numbers small enough to keep contacts truly personal, are important foundations for the mutual trust on which members rely.
During the 1990s, growth consisted primarily of consolidation within Europe, and by 1998 numbers had increased to 48 member firms. Over several years from 1999, a substantial number of firms across North America were accepted as members, then coverage began to expand to include South America, and other areas worldwide. IAG’s first member in Asia Pacific, based in Sydney, Australia, joined in 2011, and from 2013 an active campaign to find suitable members across the region has borne increasing fruit.
IAG currently has 65 member firms, and aims to achieve coverage of all major commercial regions worldwide, while remaining highly selective and maintaining the personal nature of relationships between members.