Volvo XC40 Tail Light Bulb Size

The Volvo XC40 tail light requires a specific H21W bulb size for proper illumination and function. Data for the specified component covers the range from 2019 to 2024.

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
2023-2024	H21W
2019-2021	H21W

Bulb Specifications

Description	Bulb Size
ECE standard (Europe & worldwide). Single-filament signalling bulb with BAY9s base. 12V, 21W.	H21W

Other Locations

Additional Notes

The H21W is the sole bulb type listed across all Volvo XC40 tail light specifications covered, spanning model years 2019-2024.
The H21W operates at 12 volts with a 21-watt output, classifying it as a single-filament bulb intended for signalling functions such as brake or turn signal applications rather than continuous illumination.
The H21W uses a BAY9s base, an offset bayonet fitting with a 9mm pin spacing. The asymmetric pin placement means the bulb can only be inserted in one orientation, which prevents incorrect installation.
The H21W is governed by ECE regulations, a standard recognized across Europe and numerous other markets worldwide, meaning the bulb conforms to internationally defined output and safety parameters.
Because the BAY9s base is specific to the H21W type, it is not interchangeable with the more common BAY15d or BA15s bases found on other 21-watt automotive signalling bulbs, and substitution with those types is not compatible with the Volvo XC40 tail light socket.