From Longman Business Dictionaryletter of allotmentˌletter of alˈlotment noun (plural letters of allotment) [countable]FINANCE a letter from a company to a person who has asked to buy shares in that company, telling them how many shares they have been given and if they owe any more moneyAfter you obtain a letter of allotment, you must sign it and return a copy to the company registrar.