The Franco-British boundary agreement of 1920 described an imprecisely defined boundary between Lebanon and Palestine. It appeared to pass close to the north of al-Bassa, leaving the village on the Palestinian side but cut off from much of its lands. However the French government included al-Bassa in a Lebanese census of 1921 and granted citizenship to its residents. Meanwhile, a joint British-French boundary commission was working to determine a precise border, making many adjustments in the process. By February 1922 it had determined a border that confirmed al-Bassa as being in Palestine. This became official in 1923. The citizenship of the residents was changed to Palestinian in 1926.