Volvo XC40 Dome Light Bulb Size

The Volvo XC40 rear dome light uses an H21W bulb size for replacement. The chart covers 2021 to 2022 production years with corresponding bulb size data.

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

Rear Dome Light

Years	Bulb Size
2021-2022	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 bulb type specified for the Volvo XC40 rear dome light across the 2021-2022 model years.
The H21W operates at 12 volts and 21 watts, classifying it as a single-filament bulb intended for signalling applications.
It uses a BAY9s base, which is an offset bayonet fitting. The asymmetric pin placement of the BAY9s base prevents incorrect installation of the bulb.
The H21W is governed by ECE standards, meaning it is designed for compliance with European and international regulations rather than SAE standards used in North American markets.
Due to the ECE-specific BAY9s base, the H21W is not directly interchangeable with common North American single-filament bulbs such as the 1156, which uses a BA15s base.