Marine and Naval Ratings Service Numbers


Royal Navy

The numbers of ratings consisted of a Prefix indicating their Port Division (responsible for their training, promotion and manning of ships), a forward slash, a Main Letter denoting their trade, and a 4-6 figure number. An additional letter "X" after the main letter indicates that the rating was engaged after the the new pay code of the early 1930s was introduced.

(Note: until the early 1970s Royal Navy ratings' numbers were known as 'Official Numbers' and the term was then changed to 'Service Numbers'.  At that time all ratings were given a new number on computerisation of Royal Navy pay and records accounting.   This was the first time commissioned officers were given a any number at all.)

(W) - World War 2 only

Prefix Letters
Home Port Divisions C Chatham
D Devonport
P Portsmouth
LT Lowestoft (W)
R Rosyth (W)
Overseas Port Divisions E Malta
A Alexandria (W)
Fleet Air Arm FAA (W)
L Lee-on-Solent
Main Letters
Long Service
(12 years plus optional 10 years to qualify for pension)
J Seamen and Communications
K Stokers and Mechanicians
L Officers' Stewards, some Officers' Cooks
M Others -Artificers, Electrical, Supply etc
N NAAFI staff (W)
F Fleet Air Arm
Short Service
(7 years plus 5 years on Reserve)
SS Seamen and Communications
SK Stokers
SM Miscellaneous
SF Fleet Air Arm


  • C/JX - Long service seaman from Chatham Port Division
  • D/SKX - Short service stoker from the Devonport Port Division
  • P/M - Long service, miscellaneous rating from the Portsmouth Port Division, who engaged before the new pay code into use.

Royal Marines

Some Royal Marine numbers had prefix letters as shown below (e.g. PO/1327) and sometimes there was a letter after the number indicating their trade .

(W) - World War 2 only

CH Chatham Group
PLY Plymouth Group
PO Portsmouth Group
EX Exton (W)
RMB Royal Marine Bands

Royal Marine Police guarding dock yards and depots had group prefixes as shown above with main letters "RMP" (eg. PO/RMP12345).