Sir Harold Bailey kept a great many papers, note books, diaries and photographs relating to his research and writing, and to his travels and friendships. This material has been arranged in 450 boxes and partially catalogued, funded largely by donations from members of the American Friends Committee and from the committee of the Corpus Inscriptionum Iranicarum. A preliminary list is available here. Sir Harold's correspondence files, comprising letters from over 2000 correspondents including all the major orientalists of his day, are currently being catalogued.

The van Lohuizen archives include letters, notes, drafts and other materials. These are currently being sorted and classified by Dr Ellen Raven of Leiden University.