BMW 540i License Plate Bulb Size

The BMW 540i license plate light requires a DE3423 bulb size for proper installation and function. Available data for the specified lighting component covers the range from 1994 to 2003.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Type	Shop
1997-2003	DE3423	Check Price
1994-1995	DE3423	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Festoon bulb, 41mm length, end-cap contacts. 12V.	DE3423	Check Price

Other Locations

Additional Notes

The BMW 540i uses the DE3423 bulb size across all listed model years for the license plate position, spanning 1994-2003.
The DE3423 is a festoon-type bulb, meaning it is cylindrical in shape with flat metal contacts at each end rather than a screw or wedge base.
The DE3423 operates at 12 volts, which is consistent with standard automotive electrical systems.
The bulb measures 41mm in length, a figure that determines physical fitment within the license plate housing.
The DE3423 carries ANSI standardization, meaning it conforms to specifications recognized across the United States and Canada.
Because festoon bulbs rely on end-cap contacts, substituting a wedge-base or bayonet-base bulb of similar wattage would result in an incompatible fitment regardless of voltage rating.
The 41mm length is a critical fitment factor, as festoon holders are sized to grip the bulb at a fixed span, and a bulb of a different length would not make proper contact or would not seat securely.