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When researching soldiers of the First World War, one detail can unlock a huge amount of information: the regiment number. Often confused with a general service number, regiment numbers were issued within specific units — and they hold the key to dating enlistments, identifying battalions, and tracing a man’s wartime journey.
What Are WW1 Regiment Numbers?
A regiment number was the identification number given to a soldier when he enlisted in a particular regiment. Unlike today’s Army numbers, these were not unique across the entire Army. That means two men in different regiments could both be “Private 1234” — but within their regiment, the number was unique.
How WW1 Regiment Numbers Were Assigned
Regiment numbers were usually issued sequentially by battalion or corps:
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A recruit would join at the depot or drill hall.
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He was given the next number available in that regiment’s sequence.
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Territorial Force units often had their own numbering systems until the major renumbering of 1917.
This means a regiment number is more than just digits — it’s a clue to when and where a man joined.
Common Questions About What a Service Number Means
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Same number, different regiments → Because numbering was by regiment, two soldiers in different units could both be “Private 1234.” Context (medal roll, cap badge, regiment named in record) is key.
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1917 Territorial renumbering → Huge change! Territorial soldiers were given new six-digit numbers. Both old and new numbers may appear in records.
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Prefixes and suffixes → Letters like “TR/” (Training Reserve) or “G/” (Garrison) help show the type of unit.
Why WW1 Regiment Numbers Matter in Family History Research
Understanding regiment numbers can reveal:
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Approximate enlistment date — by comparing a soldier’s number with known issue dates.
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Likely battalion — many Territorial Force battalions had unique ranges before 1917.
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Transfer history — if a man moved to another regiment, he received a new number. Tracking multiple regiment numbers can map out his service.
Common Confusions About Regiment Numbers in WW1
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Regiment vs service number → Often used interchangeably, but technically “regiment number” is the WW1 term.
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Same number, different regiments → Always check the regiment name alongside the number.
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1917 renumbering → Territorial Force soldiers received new six-digit numbers. Both old and new may appear in records.
Where to Find WW1 Regiment Numbers in the Records
Researchers can locate regiment numbers in:
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Medal Index Cards and Rolls — usually list a soldier’s regiment(s) and numbers.
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Service and pension records — when they survive.
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War diaries and casualty lists — often arranged by number.
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CWGC and Soldiers Died in the Great War databases — include regiment numbers for those killed.
In Summary: Why WW1 Regiment Numbers Are Crucial
A regiment number is more than just an administrative label. In WW1 it linked a soldier to his regiment, his comrades, and often the very moment he joined the Army. For family historians, understanding regiment numbers is the first step in unlocking service records and reconstructing a soldier’s life.
If you’ve found a WW1 regiment number but aren’t sure what it means, our expert research team can help trace the full story behind the soldier. Click the link below to see which options we offer.
Or discover more about tracing your British Army ancestor here