Where's my serial number?
- Late 1960s and later: usually on a small plate on the dashboard, visible through the windshield on the driver's side.
- Earlier cars: it varies by make and year. Common places are the driver's door pillar or hinge post, the steering column, the firewall, or near the glove box. Each make's page lists what our sources say.
- Paperwork: your title and registration also show it.
Example: A11L2231223 (an example Checker serial).
Years we cover
1960-1980.
What a Checker serial looks like, by year
Each example below is split into numbered groups of characters, with what each group means. Example numbers show the layout; they are not a specific car.
1960-1963
Looks like A11L2231223 (11 characters)
| 1 Model | 11L: A-11L, taxicab with L-head motor [CHECKER] |
| 2 Factory production order number | 223 [CHECKER] |
| 3 Serial (chassis) number of the unit | 1223 [CHECKER] |
From the 1963 Checker shop manual, pages ix and x, as reproduced by the Checker Car Club: sample A-11L-223-1223 reads model A-11L, factory production order 223, chassis number 1223 (CHECKER).
The chassis number carries no model year in this form. The club lists the section as 'early 60's cars'; the 1960 to 1963 span is our reading of that heading.
The motor (engine) number is separate, assigned by Continental Motors Corporation and found on the left side of the block (CHECKER).
Example is the club's sample.
All model codes (5)
| 11 | A-11, taxicab with overhead-valve engine [CHECKER] |
| 12 | A-12, passenger car with overhead-valve engine [CHECKER] |
| 11L | A-11L, taxicab with L-head motor [CHECKER] |
| 12L | A-12L, passenger car with L-head motor [CHECKER] |
| 12W | A-12W, station wagon with overhead-valve engine [CHECKER] |
Sources: [CHECKER]
1964-1969
Looks like A1145620001 (11 characters)
| 1 Model | 11: A-11, taxicab [CHECKER] |
| 2 Factory production order number (three or four digits) | 456 [CHECKER] |
| 3 Serial (chassis) number | 20001 [CHECKER] |
- The same character string also fits checker-1970-1979, where the first chassis digit is read as the model year.
From a 1964 or 1965 supplement to the Checker shop manual: sample A-11-456-20001 reads model A-11, factory production order 456 (three or four digits with an implied leading zero), chassis number 20001 (CHECKER).
In the 1960s the first digit of the five-digit chassis number is not a model-year digit. The club notes that the numbering changed between the 1960s and the 1970s so that a 1960s and a 1970s car could in theory share a chassis number (CHECKER).
The club document gives no year-by-year ranges for 1964 to 1969, so the 1964 to 1969 span is our reading of 'mid 60's cars' and of the 1968 and 1969 engine tables in the same document. The pattern is identical to the 1970-1979 pattern; the decoder will show both.
Example is the club's sample.
All model codes (7)
| 11 | A-11, taxicab [CHECKER] |
| 12 | A-12, passenger car [CHECKER] |
| 11E | A-11E, taxicab, 129 in. wheelbase [CHECKER] |
| 12E | A-12E, passenger car, 129 in. wheelbase [CHECKER] |
| 12W | A-12W, station wagon [CHECKER] |
| 12W6M | A-12W6M, six-door Aerobus, 154.5 in. wheelbase (1964-65 supplement) [CHECKER] |
| 12W8M | A-12W8M, eight-door Aerobus, 189 in. wheelbase [CHECKER] |
Sources: [CHECKER]
1970-1979
Looks like A11200080001 (12 characters)
| 1 Model | 11: A-11, taxicab, 120 in. wheelbase [CHECKER] |
| 2 Factory production order number (three or four digits) | 2000 [CHECKER] |
| 3 First digit of chassis number (model year) | 8: 1978 [CHECKER] |
| 4 Rest of chassis number | 0001 [CHECKER] |
- The club's 1971 parts-manual sample (A-11-450-20001) is explained with a year digit of 2 (1972), although the manual is dated 1971; the digit rule is applied to every year 0-9 here, with only 2, 8 and 9 supported by examples.
From the 1971 and 1978 Checker parts manuals as reproduced by the Checker Car Club: sample A-11-450-20001 (1971 manual) and A-11-2000-80001 (1978 manual). The chassis number is always five digits and sometimes has a sixth alpha suffix; its first digit denotes the model year (examples in the club text: 2 = 1972, 8 = 1978). The factory production order is three or four digits with an implied leading zero.
Strip dashes and spaces from the plate before entering it. A sale listing shows A12358390518F for a 1979 Marathon, read here as A-12, order 3583, chassis 90518, suffix F (the listing gives no breakdown).
Suffix letters for 1978 are documented in the club text for that year only; other years' suffix meanings are not given.
The motor number is separate: a prefix of a year digit plus letters in the 1970s tables (for example 8SB = 250 six, 1978), assigned by Chevrolet.
Example is the 1978 sample (digit 8 = 1978) with the club's sample order number; it is not a recorded car.
All model codes (6)
| 11 | A-11, taxicab, 120 in. wheelbase [CHECKER] |
| 12 | A-12, passenger car, 120 in. wheelbase [CHECKER] |
| 11E | A-11E, taxicab, 129 in. wheelbase [CHECKER] |
| 12E | A-12E, passenger car, 129 in. wheelbase [CHECKER] |
| 12W | A-12W, station wagon [CHECKER] |
| 12W8M | A-12W8M, eight-door Aerobus, 189 in. wheelbase [CHECKER] |
All first digit of chassis number (model year) codes (10)
| 0 | 1970 unconfirmed The club text gives the rule (first digit = model year) with examples for 1972 and 1978 only. [CHECKER] |
| 1 | 1971 unconfirmed The club text gives the rule (first digit = model year) with examples for 1972 and 1978 only. [CHECKER] |
| 2 | 1972 [CHECKER] |
| 3 | 1973 unconfirmed The club text gives the rule (first digit = model year) with examples for 1972 and 1978 only. [CHECKER] |
| 4 | 1974 unconfirmed The club text gives the rule (first digit = model year) with examples for 1972 and 1978 only. [CHECKER] |
| 5 | 1975 unconfirmed The club text gives the rule (first digit = model year) with examples for 1972 and 1978 only. [CHECKER] |
| 6 | 1976 unconfirmed The club text gives the rule (first digit = model year) with examples for 1972 and 1978 only. [CHECKER] |
| 7 | 1977 unconfirmed The club text gives the rule (first digit = model year) with examples for 1972 and 1978 only. [CHECKER] |
| 8 | 1978 [CHECKER] |
| 9 | 1979 Supported by a sale listing, 1979 Marathon with chassis 90518F, not by the club text. [CKLIST] |
1980
Looks like 1CMTS412XAK005261 (17 characters)
| 1 Model | T: A-11 taxicab [CHECKER] |
| 2 Wheelbase | S: 120 in. standard [CHECKER] |
| 3 Number of doors | 4: 4 [CHECKER] |
| 4 Engine type | 1: 229 Chevrolet V6 [CHECKER] |
| 5 Restraint system | 2: Type II seat belts [CHECKER] |
| 6 Check digit (X or a digit; not verified here) | X [CHECKER] |
| 7 Model year | A: 1980 [CHECKER] |
| 8 Plant | K: Kalamazoo, Michigan [CHECKER] |
| 9 Chassis number | 005261 [CHECKER] |
The supplement is dated 1981 and states A = 1980; the club text does not say whether every 1980 car carried this VIN. Cars of 1980 without it use the chassis-number forms above.
The check digit is shown as printed and is not recomputed.
Example is the manual's sample with the model-year letter changed from B to A, so it is not a recorded car.
Sources: [CHECKER]
What a serial number cannot tell you
It identifies what the factory recorded in the number: typically the model year, assembly plant, series or body and production sequence, and in some years the engine. It cannot confirm a car is original or numbers-matching. Compare stampings, body tags and documentation.