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
Kantonsbibliothek Vadiana St.Gallen 1 City: St Gallen
Country: Switzerland
KBR 43 Alternative names for repository: Koninklijke Bibliotheek van België Bibliothèque royale de Belgique Royal Library, Brussels
City: Brussels
Alternative names for city: Bruxelles
Country: Belgium
Keele University Library 4 City: Keele
Country: England, United Kingdom
Kendal Archive Centre 67 City: Kendal, Cumbria
Country: England, United Kingdom
Kent History and Library Centre 6 Alternative names for repository: Centre for Kentish Studies Kent archives Kent Archives Office East Kent Archives Centre Kent Record Office
City: Maidstone, Kent
Country: England, United Kingdom
King's College Library, University of Cambridge - City: Cambridge
Country: England
Kingston Lacy - City: Wimborne Minster
Country: England, United Kingdom
Knihovna Národního muzea 202 Alternative names for repository: National Museum Library
City: Praha
Alternative names for city: Prague
Country: Czech Republic
Kongelige Bibliotek 804 Alternative names for repository: The Royal Library Det Kongelige Bibliotek
City: Copenhagen
Alternative names for city: København
Country: Denmark
Koninklijke Bibliotheek 556 Alternative names for repository: Royal Library, The Hague KB
City: The Hague
Alternative names for city: Den Haag
Country: Netherlands
Koninklijke Nederlandse Akademie van Wetenschappen 1 Alternative names for repository: KNAW Royal Netherlands Academy of Arts and Sciences
City: Amsterdam
Country: Netherlands
Koninklijke Verzamelingen Den Haag 2297 Alternative names for repository: Royal Collections The Netherlands Royal Archive Koninklijke Verzamelingen Koninklijk Huisarchief Koninklijk Huisarchief, 's-Gravenhage
City: The Hague
Alternative names for city: Den Haag
Country: Netherlands
Kungliga Biblioteket 13 City: Stockholm
Country: Sweden