Jaguar XF Dome Light Bulb Size

The Jaguar XF dome light utilizes bulb sizes DE3423 and 12961 for interior illumination across various trim levels. Data provided for the specific components covers the period from 2009 through 2021.

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 Size
2021	DE3423
2009-2015	12961

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, 41mm length, end-cap contacts. 12V.	DE3423
Philips part number. Miniature wedge bulb (T10) with W2.1x9.5d base. 12V, 5W.	12961

Other Locations

Additional Notes

The Jaguar XF dome light specifications reference two distinct bulb types across the model's production years: the DE3423 and the 12961.
The 12961 is a Philips part number designating a miniature wedge bulb in the T10 form factor, fitted with a W2.1x9.5d base, and rated at 12V and 5W. The wedge base design means the bulb is held in place by tension from the socket rather than by a separate locking mechanism.
The DE3423 is an ANSI-standardized festoon bulb, recognized across the US and Canadian markets, with a 41mm length and end-cap contacts. Festoon bulbs make electrical contact at both ends of the bulb body rather than through a base pin or wedge.
Both bulb types operate at 12V, which is consistent with standard automotive electrical systems.
The T10 wedge base (W2.1x9.5d) of the 12961 and the end-cap contact design of the DE3423 are physically incompatible with each other, meaning the two bulb types are not interchangeable despite sharing the same operating voltage.
The Jaguar XF uses the 12961 wedge bulb for the dome light across the 2009-2015 model years.
The 2021 Jaguar XF dome light specification shifts to the DE3423 festoon bulb, which requires a socket designed to accept end-cap contacts rather than a wedge-style slot.