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
Nationaal Archief 6990 Alternative names for repository: National Archives of the Netherlands The Hague, National Archives Algemeen Rijksarchief
City: The Hague
Alternative names for city: Den Haag
Country: Netherlands
National Art Library - Alternative names for repository: The National Art Library V&A National Art Library Victoria and Albert Museum National Art Library
City: London
Country: England
National Library of Australia - Alternative names for repository: NLA
City: Canberra
Country: Australia
National Library of Ireland 13 Alternative names for repository: NLI
City: Dublin
Country: Republic of Ireland
National Library of Israel - Alternative names for repository: Jewish National and University Library
City: Jerusalem
National Library of Russia 1 Alternative names for repository: Российская национальная библиотека Bibliothèque nationale de Russie Russische Nationalbibliothek
City: St Petersburg
Alternative names for city: Leningrad
Country: Russia
National Library of Scotland, Manuscript Collections 185 City: Edinburgh
Country: Scotland, United Kingdom
National Library of Wales, Department of Collection Services 276 Alternative names for repository: NLW
City: Aberystwyth
Country: Wales, United Kingdom
National Maritime Museum, Greenwich - City: London
Country: England, United Kingdom
National Records of Scotland - Alternative names for repository: NRS Scottish Public Record Office Scottish Record Office National Archives of Scotland General Register Office for Scotland
City: Edinburgh
Country: Scotland
National Széchényi Library - City: Budapest
Country: Hungary
Natural History Museum 115 Alternative names for repository: NHM
City: London
Country: England, United Kingdom
Newcastle Literary and Philosophical Society 1 Alternative names for repository: The Lit & Phil
City: Newcastle upon Tyne
Country: England, United Kingdom
New York Public Library 106 City: New York, NY
Country: United States of America
Niedersächsisches Landesarchiv 2 Alternative names for repository: Staatsarchiv Hannover Das Niedersächsische Landesarchiv
City: Hannover
Alternative names for city: Hanover
Country: Germany
Niedersächsisches Landesarchiv, Standort Aurich 45 Alternative names for repository: Niedersächsisches Landesarchiv - Staatsarchiv Niedersächsisches Staatsarchiv, Aurich Niedersachsisches Staatsarchiv
City: Aurich
Country: Germany
Niedersächsisches Landesarchiv, Standort Wolfenbüttel - Alternative names for repository: Niedersächsisches Landesarchiv, Standort Wolfenbuettel Niedersächsisches Staatsarchiv Wolfenbüttel
City: Wolfenbüttel
Alternative names for city: Wolfenbuttel Wolfenbuettel
Country: Germany
Northamptonshire Record Office 8 City: Northampton
Country: England, United Kingdom
Nottingham University Library 4 City: Nottingham
Country: England, United Kingdom
Národní knihovna 25 Alternative names for repository: Klementinum National Library of the Czech Republic
City: Praha
Alternative names for city: Prague
Country: Czech Republic