- Main article: List of Surviving Lonsdale Records
The list of Lonsdale Records relating to the Lowther family and the Earls of Lonsdale are stored at the Cumbria Record Office (Carlisle Headquarters). The Lowther Family Estate have thousands of records listed in various categories and sub-categories ranging from DLons/L5 to DLons/L25. The records relating to the 11th Border Regiment (Lonsdale) range from DLons/L13/13/1 to DLons/L13/13/282
D LONS/L13/13/239–246
12th (Reserve) Battalion / Issue and receipt voucher books
- D LONS/L13/13/239: Issue and receipt voucher book - date: 17 April - 6 November 1915
- D LONS/L13/13/240: Issue and receipt voucher book - date: 19 December 1915 - 6 March 1916
- D LONS/L13/13/241: Issue and receipt voucher book - date: 8 March - 14 July 1916
- D LONS/L13/13/242: Issue and receipt voucher book - date: 15 July - 10 August 1916
- D LONS/L13/13/243: Issue and receipt voucher book - date: 6 July - 5 September 1916
- D LONS/L13/13/244: Monthly returns of arms, ammunition, equipment, public clothing and barrack stores - date: September - October 1916
- D LONS/L13/13/245: Papers re: personal clothing, arms, camp kit, footwear, leather goods, setting up of shoemakers' shop, uniform, typewriter and stationery, and other equipment - date: April 1915 - 20 November 1916
- D LONS/L13/13/246: Papers re the design and supply of silver cap badges which were donated by the Earl of Lonsdale - date: 12 October 1914 - 2 August 1917
—For access to the above records please contact the Cumbria Archive Centre (Carlisle)