Change to he numbering of TF RAMC troops was promulgated in Army Council Instruction (ACI) 380 of 1917, published on 3 April 1917. As in the other arms, ACI 380 also dealt with changes in the arrangements for TF records, pay and other administrative matters. These arrangements were to take effect from 1 April 1917, but were later postponed until 1 June 1917. Although not explicitly stated in ACIs, it is likely these postponements also applied to renumbering.

Regulars (and therefore also men serving in the new armies) retained their existing numbers in the range 1 - 300000, TF soldiers were allocated new numbers from 300001 upwards. The blocks of numbers allocated to specific units are listed below.

After the renumbering came into effect, the only men who were treated as TF for RAMC numbering were:

Regular soldiers transferred from other arms or Class B Reservists posted to RAMC units (TF or regular) received regular RAMC numbers.

ACI 380 noted that men from a number of RAMC TF units earmarked for disbandment (upon the formation of Home Service Field Ambulances) were to be treated as regulars. These were -

3/1 Highland Field Ambulance 2/2 Highland Field Ambulance 2/1 Lowland Field Ambulance 2/2 Lowland Field Ambulance 2/3 Lowland Field Ambulance

2/1 Welsh Field Ambulance 2/2 Welsh Field Ambulance 2/3 Welsh Field Ambulance 3/1 East Anglian Field Ambulance 2/2 East Anglian Field Ambulance 2/3 East Anglian Field Ambulance

1 Cyclist Bde Field Ambulance 2 Cyclist Bde Field Ambulance 3 Cyclist Bde Field Ambulance 4 Cyclist Bde Field Ambulance 5 Cyclist Bde Field Ambulance 6 Cyclist Bde Field Ambulance 7 Cyclist Bde Field Ambulance 8 Cyclist Bde Field Ambulance 9 Cyclist Bde Field Ambulance 10 Cyclist Bde Field Ambulance

1 Mounted Bde Field Ambulance 2 Mounted Bde Field Ambulance 3 Mounted Bde Field Ambulance

From	To	Unit		County Association
300001	301000		Highland Mtd Bde Field Ambulance	Inverness
301001	303000	1	Highland Div Field Ambulance	Aberdeen (City)
303001	305000	2	Highland Div Field Ambulance	Aberdeen (City)
305001	307000	3	Highland Div Field Ambulance	Dundee (City)
307001	308000		Highland Div CCS	Aberdeen (City)
308001	310000	1	Scottish General Hospital	Aberdeen (City)
310001	311000		Highland Div Sanitary Section	Aberdeen (City)
311001	315000		Scottish Horse Mtd Bde Field Ambulance	Perth
315001	316000		Lowland Mtd Bde Field Ambulance	Glasgow (City)
316001	318000	1	Lowland Div Field Ambulance	Glasgow (City)
318001	320000	2	Lowland Div Field Ambulance	Glasgow (City)
320001	322000	3	Lowland Div Field Ambulance	Edinburgh (City)
322001	323000		Lowland Div CCS	Glasgow (City)
323001	324000		Lowland Div Sanitary Section	Glasgow (City)
324001	326000	2	Scottish General Hospital	Edinburgh (City)
326001	328000	3	Scottish General Hospital	Glasgow (City)
328001	330000	4	Scottish General Hospital	Glasgow (City)
330001	331000	329	Field Ambulance (Home Service)	Glasgow (City)
331001	332000	335	Field Ambulance (Home Service)	Glasgow (City)
332001	333000	338	Field Ambulance (Home Service)	Glasgow (City)
333001	337000	339	Field Ambulance (Home Service)	Glasgow (City)
337001	339000	1	West Lancs Field Ambulance	West Lancs
339001	341000	2	West Lancs Field Ambulance	West Lancs
341001	343000	3	West Lancs Field Ambulance	West Lancs
343001	344000		West Lancs CCS	Westmorland
344001	345000	1	Western General Hospital	West Lancs
345001	350000		West Lancs Sanitary Section	West Lancs
350001	352000	1	East Lancs Field Ambulance	East Lancs
352001	354000	2	East Lancs Field Ambulance	East Lancs
354001	356000	3	East Lancs Field Ambulance	East Lancs
356001	357000		East Lancs CCS	East Lancs
357001	359000	2	Western General Hospital	East Lancs
359001	362000		East Lancs Sanitary Section	East Lancs
362001	363000		Welsh Border Mtd Bde Field Ambulance	Chester
363001	364000		South Wales Mtd Bde Field Ambulance	Hereford
364001	366000	1	Welsh Field Ambulance	Monmouth
366001	368000	2	Welsh Field Ambulance	Glamorgan
368001	370000	3	Welsh Field Ambulance	Glamorgan
370001	371000		Welsh Div CCS	Glamorgan
371001	372000		Welsh Div Sanitary Section	Glamorgan
372001	374000	3	Western General Hospital	Glamorgan
374001	375000	301	Field Ambulance (Home Service)	Glamorgan
375001	376000	302	Field Ambulance (Home Service)	Glamorgan
376001	377000	303	Field Ambulance (Home Service)	Glamorgan
377001	378000	322	Field Ambulance (Home Service)	Monmouth
378001	379000	323	Field Ambulance (Home Service)	Monmouth
379001	380000	324	Field Ambulance (Home Service)	Monmouth
380001	381000	325	Field Ambulance (Home Service)	Monmouth
381001	382000	326	Field Ambulance (Home Service)	Monmouth
382001	383000	331	Field Ambulance (Home Service)	Monmouth
386001	388000	1	Northumbrian Field Ambulance	Northumberland
388001	390000	2	Northumbrian Field Ambulance	Durham
390001	392000	3	Northumbrian Field Ambulance	East Riding
392001	393000		Northumbrian CCS	Northumberland
393001	395000	1	Northern General Hospital	Northumberland
395001	400000		Northumbrian Sanitary Section	East Riding
400001	401000		Yorkshire Mtd Bde Field Ambulance	West Riding
401001	403000	1	West Riding Field Ambulance	West Riding
403001	405000	2	West Riding Field Ambulance	West Riding
405001	407000	3	West Riding Field Ambulance	West Riding
407001	408000		West Riding CCS	West Riding
408001	410000	2	Northern General Hospital	West Riding
410001	412000	3	Northern General Hospital	West Riding
412001	415000		West Riding Sanitary Section	West Riding
415001	416000		North Midland Mtd Bde Field Ambulance	Stafford
416001	417000		Notts & Derby Mtd Bde Field Ambulance	Nottingham
417001	419000	1	North Midland Field Ambulance	Derby
419001	421000	2	North Midland Field Ambulance	Leicester
421001	423000	3	North Midland Field Ambulance	Stafford
423001	424000		North Midland CCS	Derby
424001	426000	4	Northern General Hospital	Lincoln
426001	428000	5	Northern General Hospital	Leicester
428001	433000		North Midland Sanitary Section	Leicester
433001	434000	1	South Midland Mtd Bde Field Ambulance	Warks
434001	435000	2	South Midland Mtd Bde Field Ambulance	Buckingham
435001	437000	1	South Midland Field Ambulance	Warks
437001	439000	2	South Midland Field Ambulance	Warks
439001	441000	3	South Midland Field Ambulance	Gloucester
441001	442000		South Midland CCS	Warks
442001	444000	1	Southern General Hospital	Warks
444001	446000	2	Southern General Hospital	Gloucester
446001	448000	3	Southern General Hospital	Oxford
448001	449000		South Midland Sanitary Section	Buckingham
449001	450000	304	Field Ambulance (Home Service)	Gloucester
450001	451000	305	Field Ambulance (Home Service)	Gloucester
451001	455000	306	Field Ambulance (Home Service)	Gloucester
455001	456000	1	South Western Mtd Bde Field Ambulance	Wilts
456001	457000	2	South Western Mtd Bde Field Ambulance	Somerset
457001	459000	1	Wessex Field Ambulance	Devon
459001	461000	2	Wessex Field Ambulance	Devon
461001	463000	3	Wessex Field Ambulance	Southampton
463001	464000		Wessex CCS	Devon
464001	465000		Wessex Sanitary Section	Devon
465001	467000	4	Southern General Hospital	Devon
467001	472000	5	Southern General Hospital	Southampton
472001	473000		Eastern Mtd Bde Field Ambulance	Bedford
473001	475000	1	East Anglian Field Ambulance	Suffolk
475001	477000	2	East Anglian Field Ambulance	Norfolk
477001	479000	3	East Anglian Field Ambulance	Essex
479001	480000		East Anglian CCS	Suffolk
480001	481000		East Anglian Sanitary Section	Cambridge
481001	483000	1	Eastern General Hospital	Cambridge
483001	484000	319	Field Ambulance (Home Service)	Norfolk
484001	485000	320	Field Ambulance (Home Service)	Norfolk
485001	486000	321	Field Ambulance (Home Service)	Norfolk
486001	487000	333	Field Ambulance (Home Service)	Norfolk
487001	488000	336	Field Ambulance (Home Service)	Norfolk
488001	492000	337	Field Ambulance (Home Service)	Norfolk
492001	493000		South Eastern Mtd Bde Field Ambulance	Kent
493001	495000	1	Home Counties Field Ambulance	Kent
495001	497000	2	Home Counties Field Ambulance	Kent
497001	499000	3	Home Counties Field Ambulance	Surrey
499001	500000		Home Counties CCS	Surrey
500001	502000	2	Eastern General Hospital	Sussex
502001	503000	307	Field Ambulance (Home Service)	Kent
503001	504000	308	Field Ambulance (Home Service)	Kent
504001	505000	309	Field Ambulance (Home Service)	Kent
505001	508000		Home Counties Sanitary Section	Surrey
508001	510000	1	London Field Ambulance	London (City)
510001	512000	2	London Field Ambulance	London (City)
512001	514000	3	London Field Ambulance	London (City)
514001	515000	1	London CCS	London (City)
515001	517000	1	London General Hospital	London (City)
517001	519000	2	London General Hospital	London (City)
519001	521000	5	London General Hospital	London (City)
521001	522000	310	Field Ambulance (Home Service)	London (City)
522001	523000	311	Field Ambulance (Home Service)	London (City)
523001	524000	312	Field Ambulance (Home Service)	London (City)
524001	525000	327	Field Ambulance (Home Service)	London (City)
525001	526000	328	Field Ambulance (Home Service)	London (City)
526001	527000	332	Field Ambulance (Home Service)	London (City)
527001	531000	1	London San Coy	London (City)
531001	533000	1	London Div Sanitary Section	London (City)
533001	534000		London Mtd Bde Field Ambulance	London (County)
534001	536000	4	London Field Ambulance	London (County)
536001	538000	5	London Field Ambulance	London (County)
538001	540000	6	London Field Ambulance	London (County)
540001	541000	2	London CCS	London (County)
541001	543000	3	London General Hospital	London (County)
543001	545000	4	London General Hospital	London (County)
545001	550000	2	London San Coy	London (County)
550001	551000	313	Field Ambulance (Home Service)	London (County)
551001	552000	314	Field Ambulance (Home Service)	London (County)
552001	553000	315	Field Ambulance (Home Service)	London (County)
553001	554000	330	Field Ambulance (Home Service)	London (County)
554001	555000	334	Field Ambulance (Home Service)	London (County)
555001	556000	340	Field Ambulance (Home Service)	London (County)
556001	557000	341	Field Ambulance (Home Service)	London (County)
557001	558000	342	Field Ambulance (Home Service)	London (County)
558001	559000	343	Field Ambulance (Home Service)	London (County)
559001	560000	344	Field Ambulance (Home Service)	London (County)
560001	561000