In 1864, the Ionian Islands united with Greece. A new charter made IB a "Société Anonyme", with the Greek government assuming its debt. That year too IB converted its agencies in Athens and Patras to full branches (possibly before 1864.) IB then extended its operations to the rest of Greece. The Athens office took over as Head Office from the Corfu office in 1873. By 1880 the bank had lost its legal monopoly position in the Islands, but gained an extension to its (no longer exclusive) right of note issue. In 1883, IB gave up its Royal Charter and registered as a limited liability company.