What Is a Service Number? Find Your Ancestor's Record Fast

Scholarship deadlines have a way of turning family history into a race. Most veteran-descendant scholarships ask you to demonstrate a link to Australian service - and the cleanest way to do that's with your ancestor's service record. The cleanest way to find that record? Their service number.

A service number is the unique identifier issued to everyone who enlisted in Australia's armed forces. Think of it as the catalogue number for their file at the National Archives of Australia. Search by name alone and you might wade through dozens of John Smiths; search with the number and you land on the right file in one go. When you're weeks out from an AVCAT closing date or the Gallipoli Scholarship Fund's cut-off, that difference matters.

This guide covers how service numbers worked across the Army, Navy and Air Force in both World Wars, what all those letter prefixes actually mean, and the quickest places to find a number when you're starting from nothing but a surname.

Why scholarship applicants should care about a number from 1942

Programs like the Long Tan Bursary, AVCAT's sponsored scholarships and Legacy's education support are built around descent from, or connection to, someone who served. Some ask for formal documentation; others simply expect you to tell the story of that service convincingly. Either way, the service record is your primary source - and the service number is the shortest path to it.

There's a second benefit that's easy to miss. The number itself carries information. Before you've opened a single file, a WWII Army number can tell you which state your ancestor enlisted in, which force they joined, and roughly how early in the war they signed up. That's genuinely useful background when you're drafting the personal statement most scholarship applications require.

WWI: regimental numbers, and why they're messier than you'd expect

Here's the first surprise for anyone researching a First World War ancestor: strictly speaking, they never had a "service number" at all. What they had was a regimental number - and the system behind it was decidedly loose.

Every battalion, light horse regiment and corps ran its own numbering sequence, generally beginning at 1. Tradition held that number 1 went to the Regimental Sergeant Major as a mark of seniority. Crucially, nothing stopped two units from using the same numbers, so "1234" in the 1st Battalion and "1234" in the 7th Battalion were two entirely different men. A regimental number only identifies someone when it's paired with their unit.

Officers weren't given numbers at all, and neither were nurses - so if your family's connection to service runs through a great-great-grandmother in the Australian Army Nursing Service, you'll find her record filed under name and rank rather than a number. That's normal, not a dead end.

Transfers added more wrinkles. A soldier moving between units might keep his existing number (if nobody in the new unit already held it), be issued a fresh one, or have a letter tacked on to break the tie - producing numbers like 1234A or 567B. Men who re-enlisted frequently picked up an "R" suffix.

The system tightened up from 1917. Rather than assigning reinforcements to specific units before they sailed, the AIF pooled them as "general reinforcements" and gave them unique numbers between 50,000 and 80,000 - an early move towards one-person-one-number. The regimental scheme was finally scrapped in 1921, replaced by unique army numbers that stayed with a soldier for their whole period of service.

WWII: the prefix system decoded

By the Second World War the lesson had been learned. Every member of the Second Australian Imperial Force received a unique Army number - theirs alone, never recycled. And this time the number came with a prefix of one or more letters that encodes two facts at a glance: where the person enlisted, and which force they belonged to.

The state letter

The opening letter marks the Military District - in practice, the state or territory of enlistment:

NGX and PX were the two special cases, covering Europeans who signed up overseas in New Guinea and Papua respectively.

The X

The X following the state letter signals enlistment in the 2nd AIF. NX reads as "New South Wales, 2nd AIF"; VX as "Victoria, 2nd AIF". The most famous example is General Sir Thomas Blamey, commander of all Australian forces in WWII, who held VX1 - the very first Victorian enlistment.

Extra letters you'll encounter

As the war went on, additional letters were slotted in to cover particular situations:

So if the number in your family papers is something like VFX61330, you're looking at a servicewoman - perhaps AWAS, AAMWS or an army nurse - and her record is searchable exactly the same way as any man's.

Militia numbers, and why one person can have two

Plenty of WWII service happened outside the AIF. The Citizen Military Forces - the Militia - used the same state letters but dropped the X. When Militia soldiers transferred into the AIF, they commonly carried their old number across with 100,000 added; Permanent Military Forces officers had 200,000 added instead.

The upshot: finding two different numbers for the same ancestor isn't a mistake in the records. One number covers their Militia service, the other their AIF service. Some careers collected even more - Lieutenant Colonel Kathleen Best was issued five separate numbers over the course of her service as the systems changed around her.

Reading the number itself

Numbers were handed out sequentially from 1 within each state, which means a low number points to early enlistment - NX1 signed up well before NX50000. If a scholarship essay asks you to reflect on your ancestor's service, "enlisted in the opening months of the war" versus "called up in 1943" is exactly the kind of detail the number alone can suggest, ready to be confirmed once the full record arrives.

Navy numbers: pay numbers and port prefixes

The Royal Australian Navy ran its own arrangements, entirely separate from the Army. During WWII, RAN officers had no official service numbers - instead they carried "pay numbers" for administrative purposes. Ratings (non-commissioned sailors) in the Permanent Naval Force did receive official numbers, issued plain with no letter prefixes.

Reserve ratings are where the letters appear, and they indicate the port of enlistment: S for Sydney, PM for Port Melbourne, F for Fremantle, B for Brisbane, H for Hobart, PA for Port Adelaide and W for Williamstown. Members of the Royal Australian Naval Volunteer Reserve had an oblique stroke and a "V" appended to the prefix - PA/V, for instance. Standardised personal numbers with category prefixes didn't reach the whole Navy until 1966.

RAAF numbers: blocks, not prefixes

The Royal Australian Air Force took a third approach. WWII RAAF numbers carried no letter prefixes at all - just plain numbers, issued in blocks allocated state by state. The block told you the role: 400,001 to 459,999 was reserved for aircrew, while ground crew drew numbers from 1 to 299,999. In day-to-day use a letter sometimes appeared in front of the number to flag the member's status category, but it was never part of the official number.

Every RAAF number was unique and never reassigned, so a number found on a WAAAF great-aunt's discharge certificate or an uncle's log book identifies exactly one person - which makes RAAF ancestors some of the easiest to pin down.

Don't have a number? Five places to find one fast

Starting with nothing but a name and a family story? Work through these in order - they're ranked by how quickly they tend to deliver.

1. DVA Nominal Rolls

The Department of Veterans' Affairs publishes searchable online Nominal Rolls covering WWII, Korea, Vietnam and the First Gulf War at nominal-rolls.dva.gov.au. The WWII roll alone lists over one million people across the Army, Navy, RAAF and Merchant Navy. A surname search returns the service number plus rank, unit, dates and place of enlistment - often everything a scholarship form asks for in a single hit.

2. AWM Embarkation Roll (WWI)

For First World War ancestors, the Australian War Memorial's Embarkation Roll records roughly 330,000 AIF personnel as they left Australia, including regimental number, unit, age, occupation, address and next of kin. The AWM's People search covers this and several other nominal rolls in one query.

3. The AIF Project (WWI)

Run by UNSW Canberra, the AIF Project is a searchable database of the 330,000 men and women who served overseas with the First AIF. Because it pulls together multiple sources, it's often friendlier than RecordSearch when you're starting cold.

4. NAA RecordSearch (every conflict)

If the rolls come up empty, go to the National Archives' RecordSearch and use the NameSearch function - enter the surname and pick the conflict category. Item titles usually list the service number along with place of birth and place of enlistment, which is how you tell apart several people sharing a name. Our guide to requesting war records from the NAA walks through the whole process.

5. The shoebox in the cupboard

Before you search anywhere online, check the house. Service numbers turn up on discharge certificates, letters of service, pay books, identity discs, engraved medals and old correspondence from the Department of Defence or the Repatriation department. Even a number pencilled on the back of a photograph is enough to launch a proper search.

Got the number? Here's what it unlocks

The number confirms when and where someone enlisted - but the full service record is where the story lives: the attestation form, the service and casualty form, the discharge papers. That's the document that substantiates a scholarship application and fills a personal statement with real detail. Depending on the conflict, much of it's already digitised, and once you have it you can trace where your ancestor served overseas and pull out the five most useful things a war record reveals.

Fair warning: service records are dense with handwritten entries, unit codes and military abbreviations that don't explain themselves. If yours arrives looking like a puzzle, our decode service at decodemydigger.com.au/upload turns the record into plain language for $59 AUD - every abbreviation translated, every date mapped to real events, every posting explained.

Quick reference: where to find a service number

Common questions

What does NX on a service number mean?

The person enlisted in New South Wales (N) with the Second Australian Imperial Force (X). The first letter always marks the state or territory of enlistment; the X marks 2nd AIF membership during WWII. The other state prefixes are VX (Victoria), QX (Queensland), SX (South Australia), WX (Western Australia), TX (Tasmania) and DX (Northern Territory).

What's the fastest way to find an ancestor's number?

Search the DVA Nominal Rolls at nominal-rolls.dva.gov.au by surname and conflict. For WWI, use the AWM Embarkation Roll or the AIF Project instead. Then take the number to RecordSearch to locate the full record.

Did WWI soldiers have service numbers at all?

They had regimental numbers, which weren't unique across the army - each unit numbered its own men from 1, so the same number could belong to several soldiers in different units. Officers and nurses had no numbers. Unique army numbers replaced the regimental system in 1921.

Why does my ancestor have two numbers?

Usually because they served in the Militia (CMF) before volunteering for the 2nd AIF - one number for each. Transferring Militia soldiers often kept their old number with 100,000 added, and later conflicts brought further renumbering as systems changed.

Does Australia still use service numbers?

No. They were phased out across 2000 and 2001, when the Department of Defence moved to employee numbers under an integrated personnel management system called PMKeyS.

Where to next

The service number gets you to the record; the record gets you to the application. Browse the free scholarship database to see every scholarship open to descendants of Australian veterans - including DVA's education schemes - and check the step-by-step application guide before deadlines creep up. And if the record you've found reads like code, we'll decode it into plain English for $59 AUD at decodemydigger.com.au/upload.