Significance or otherwise of sequential service numbers

[Kaniere]

Often information about a single soldier is missing from the accessible records. It occurred to me that it might be possible to obtain useful information about them from the records of others recruited at the same time and place, or who served together.

How and when were service numbers assigned?

Does it follow that those with sequential service numbers were attested at the same time, or underwent basic training together, or assigned to the same unit and therefore might have known each other? 

[Keith_history_buff]

I hope you find the following of interest. 
https://armyservicenumbers.blogspot.com/p/index.html

The challenge is that although infantry regiments had their own number sequence, a number was not unique to a regiment. Chalky White could be 9999 and to have enlisted under Territorial Force terms of service 12 months ago, Nobby Clark could be 9999 and to have enlisted under Special Reserve terms of service 6 months ago, and Tommy Atkins  could be 9999 and to have enlisted under Regular terms of service 1 week ago. 

This confusion led to the renumbering in August 1920, with what would be termed as an unique identifier in today's parlance. 

Up until 1908, the Royal Navy had been issuing six digit Official Numbers to its ratings. These had been issued from 1894 onwards, and prior to that date, they had been five digits in length.

[PRC]

2 hours ago, Kaniere said:

It occurred to me that it might be possible to obtain useful information about them from the records of others recruited at the same time and place, or who served together.

A "near number" surviving record search is frequently advocated as one way to address the problem of a missing service record for an individual soldier - looking to see if recurring patterns occurred not just on enlistment but for any subsequent changes that led to a new service number being issued. But with so many different numbering schemes in place, the 1917 renumbering of the Territorial Force and the occasional tendency to put a batch of numbers aside for a unit specific purpose, it's difficult to give any concise ground rules.

Best thing is either to do a worked example by giving us the name, service number and unit of the man that you're interested in.

Or have a browse through the threads  - I suspect you won't have to look far to find a few responses that draw on the "near number" approach

Cheers,
Peter