Chassis Coding

Chassis numbering system, up to July 1970
Prefix letters
Suffix letters
Chassis Number Format, from July 1970 on
Product Code; Serial Number; Service Code
Trim Codes and Paint Codes

Earlier Chassis numbering system, up to July 1970

Prefix letters

All early Imps have a B prefix (as an 'A' denotes period 1950 - 1959 and prefix letter 'B' denotes model period 1960 - 1969). From '69 on, Imps lost their prefix.
(Prefix letters 'LB' indicate Linwood manufacture.)

Product Codes

The first three figures indicate the model. The next six digits are the Serial Number.
(If a car was exported in C.K.D. form (completely knocked down) then a 9 was put after the product code.)

Mark / Type	'Rootes'	sometimes	'Chrysler' (from '69 on)	announced	last car (maybe)
(basic) Hillman Imp	423
Hillman Imp Mk I	421	429
Hillman Imp de Luxe Mk I	411	419
Hillman Imp de Luxe Mk II	412		413
Hillman Imp Super	442		443
Hillman Californian	401	443	402		'69: 2329
Hillman Husky	481		482
Commer Imp Van	462
Hillman Imp Van	463
Singer Chamois Mk I	431 ?	543 ?
Singer Chamois Mk II	543 ?	732 ?	733 ?		'70 Apr. B733006587
Singer Chamois Sport	792		793		'69: 548
Singer Chamois Coupe	721		722		'69: 940
Sunbeam Imp Sport	492		493
Sunbeam Sport	593			L5 593 139499
Sunbeam Chamois	733 ?	543 ?
Sunbeam Chamois Coupe	523
Sunbeam Stiletto	301		302		4835
Sunbeam Californian	401

Suffix letters

Three letters, indicating the following:

First letter

H - Home
R - R.H.D. Export
L - L.H.D. Export
E - C.K.D. Export Home Specification   (C.K.D.= completely knocked down)
W - C.K.D. R.H.D. Export
X - C.K.D. L.H.D. Export

Second letter

C - Convertible
H - Hardtop
L - Limousine
R - Roadster
S - Saloon
P - Pick-up
U - Estate Car
V - Van
X - Chassis only

Third letter

M - Ministry of Supply
O - Standard
X - Non-Standard
P - Police Specification

Example: a Dutch owned Sunbeam Chamois (1969 Feb) may have the following chassis number B 733 000683 LSO, in which LSO stands for L = left hand drive (export); S = Saloon; O = standard
However, a Stiletto that I know (1970 July) has no. LB 302 003034 LCO - Therefore C does not only stand for convertible but assumeably for coupé as well...

New Chassis Number Format

A new vehicle identification format was introduced in July 1970.

New chassis plate example:

Chassis No.	G 302 631590
Service Code	B SA X	Paint Code	108
Trim Code	701	Type Code	211 H 4

Chassis No.

The Plant is indicated by the 1st letter:

L = Linwood
R = Ryton

The Series by the 2nd letter or digit

July 1970: G Series
July 1971: H Series
July 1972: 3 Series
July 1973: 4
July 1974: 5
July 1975: 6

The Product Code is indicated by the next 3 digits

(The same codes were used as previously.)

The Serial Number is the next six digits. These show the total production of all Imps derivatives since July 1970.

Commencing 000001 = Ryton
Commencing 600001 = Linwood
Commencing 900001 = C.K.D.

Example: my Stiletto, exported to Holland (1971 March): G 302 631590 BSA.
BSA refers to the Service Code.

Service Code

The Engine Code (1st letter):

A = Imp, 875cc Low Compression
B = Imp, 875cc High Compression
H = High compression [earlier]

The Transmission Code (2nd letter or number):

C = standard transmission [earlier]
S = Standard transmission, Imp [later]

The Option Code (3rd letter):

A = No other option
B = Servo brakes
C = Servo brakes and radio
D = Servo brakes and heavy duty suspension
E = Servo brakes, heavy duty suspension and radio
F = Radio
G = Radio and heavy duty suspension
H = Heavy duty suspension

The Market Area (4th letter):

H = Home, R.H.D. [later]
E = Export, R.H.D.
O = r.h.d. [earlier]
X = Export, L.H.D.

There's a Super Imp registered as PPR 276R on 1 December 1976 with chassis no. RICBA6L103422
Peter Fitzgerald has a 75 Super with Vin number R1CBA5L113581 and a service number which conforms to the L5 443 113581 BSAH format.

Most R registered Imps are Caledonians.

Much of the information given here was taken from Production figures & Chassis numbers / by Jack Salter. - Impressions 1987 August

UK Registration Plates - Year Identifiers

Suffix Letters