Note: every manifestation of a letter is counted, so the number of documents in a repository may be larger than the number of letters.

Repository Number of documents Further details
Tartu University Library - Alternative names for repository: Universitätsbibliothek, Tartu Tartu Ülikooli Raamatukogu
City: Tartu
Country: Estonia
Texas Christian University Library 2 City: Fort Worth, TX
Country: United States of America
Teylers Stichting 6 Alternative names for repository: Teylers Museum
City: Haarlem
Country: Netherlands
The Huguenot Library, University College London Special Collections 3 Alternative names for repository: The Huguenot Society Library
City: London
Country: England, United Kingdom
The Morgan Library & Museum 16 Alternative names for repository: Pierpont Morgan Library
City: New York, NY
Country: United States of America
The National Archives (UK) 949 Alternative names for repository: TNA Public Record Office, National Archives, Kew Public Record Office, London PRO
City: Kew, Richmond, Surrey
Country: England, United Kingdom
The Vyne 9 City: Sherborne St John
Country: England
Thüringer Universitäts- und Landesbibliothek, Jena 1 City: Jena
Country: Germany
Thüringisches Hauptstaatsarchiv Weimar - Alternative names for repository: Landeshauptarchiv Weimar
City: Weimar
Country: Germany
Tresoar 47 Alternative names for repository: Fries Historisch en Letterkundig Centrum Frysk Histoarysk en Letterkundich Sintrum Provinciale Bibliotheek Friesland Provincial Libary, Leeuwarden
City: Leeuwarden
Country: Netherlands
Trinity College Dublin 11 Alternative names for repository: TCD
City: Dublin
Country: Republic of Ireland
Trinity College Library, University of Cambridge 19 City: Cambridge
Country: England, United Kingdom