The 14th (Reserve) Battalion, The Royal Sussex Regiment, adopted the same number series as the 11th, 12th and 13th (South Down) Battalions and was a local reserve battalion for these.
Soldiers Died in The Great War notes the highest SD/ prefixed number as SD/5943 Sgt Arthur Whitlock MM who died whilst serving with the 9th Battalion, Royal Sussex Regiment. My data for the 14th (Reserve) Battalion starts in the low 5000s and extends to the low 6000s, sample army service number data and dates below. Men joining the 14th (or later called up to the 14th having attested under the Derby Scheme) were posted not only to the South Down battalions but also to other Sussex Regiment battalions as needed, and later Training Reserve battalions.
SD/5025 joined on 26th October 1915
SD/5050 joined on 10th November 1915
SD/5200 joined on 5th January 1916
SD/5466 joined on 30th March 1916
SD/5617 joined on 4th April 1916
SD/5946 joined on 23rd May 1916
SD/5977 joined on 2nd June 1916
SD/6369 joined on 8th July 1916
The majority of recruits to this battalion from March 1916 appear to be men who attested under the Derby Scheme in November and December 1915.
Looking for medals? I have Royal Sussex Regiment medals for sale,including medals to men who served with the South Down battalions.
I also offer a comprehensive, fast and cost-effective military history research service. Follow the link for more information.