The chaßis number of the Fiesta contains information on the production date and plant. The structure of the chaßis number may differ from the following one in single cases, in particular concerning positions 5 and 6. The manufacturer may (positions 1-3) be left out of the chaßis number as well.

The chaßis number can be decoded as follows:1 2
Positions 01 - 03: Code of manufacturer: WFO = Ford-Werke AG (Germany), SFA = Ford Motor Company Ltd. (UK), VS6 = Ford España S.A. (Spain).
Positions 04 - 04: Chaßis form: B = 3-doors limousine.
Positions 05 - 06: Unused positions.
Positions 07 - 07: Country of manufacture: G = Germany, B = UK, W = Spain.
Positions 08 - 08: Plant: A = Cologne (Germany) / Dagenham (UK) (depending on country of manufacture), C = Saarlouis (Germany), P = Valencia (Spain).
Positions 09 - 09: Model code: F and J = Fiesta.
Positions 10 - 10: Chaßis form: as above.
Positions 11 - 11: Year of manufacture: see table below.
Positions 12 - 12: Month of manufacture: see table below.
Positions 13 - 17: 5-digit consecutive production number.
Example of a chaßis number WFOBXXGAFBBD99999: A 3-doors Fiesta limousine built in November 1981 in Cologne by Ford Germany, with production number 99999.