« Reply #6 on: Thursday 10 September 15 13:14 BST (UK) »
FindMyPast has a Royal Artillery attestation in 1919 for a Joseph Samuel Miller b abt 1900 in Middlesborough, it gives a service number of 1018696 and a former service number of 285210. It sounds like he must have been in a different regiment previously. But as he's only 19 it can't have been for long. Do either of these numbers match what you know.?
What age is given on marriage cert?
Marriage cert should also give his father's name and occupation
(just saw you said his father's name was samuel)
Berks / Oxon: Eltham, Annetts, Wiltshire (surname not county), Hawkins, Pembroke, Partridge
Dorset / Hants: Derham, Stride, Purkiss, Sibley
Yorkshire: Pottage, Carr, Blackburn, Depledge
Sussex: Goodyer, Christopher, Trevatt
Lanark: Scott (soldier went to Jersey CI)
Jersey: Fowler, Huelin, Scott