ECE Regulation
ECE R48 — where every lamp on a vehicle must sit.
R48 is the master installation regulation. It defines which lamps are mandatory, which are optional, where they may be mounted, and how they must switch. Individual lamp regulations (R7 for position, R87 for DRL, R65 for beacons) certify the lamp itself. R48 certifies the vehicle on which the lamps are fitted.
Laatst bijgewerkt 24 april 2026
Mandatory vs. optional lamps
R48 splits lamps into three categories: mandatory (must be fitted), optional (may be fitted), and prohibited (must not be fitted). The list grows with the vehicle's weight class and intended use.
For an N3 truck (above 12 tonnes) the mandatory list includes: headlamps (passing and driving), front and rear position lamps, end-outline marker lamps (for vehicles over 2.1 m wide), stop lamps, direction indicators, reversing lamp, rear fog lamp, licence plate lamp, and side marker lamps on any bodywork longer than 6 metres.
Optional but commonly fitted: DRL (R87), front fog lamps, additional rear fog lamps on trailers, and auxiliary high-beams. Anything outside the mandatory-or-optional list is prohibited.
Mounting-height rules that trip people up
R48 specifies mounting heights for every lamp class as a range (min and max), measured from ground level with the vehicle unladen. The common traps:
- Rear fog lamps must be between 250 mm and 1000 mm from the ground, and at least 100 mm from any stop lamp. A retrofit fog lamp mounted too close to the brake light is an R48 failure. - Position lamps must be at least 350 mm from the vehicle's outer edge and no more than 400 mm. Marker lamps on a wide trailer outside this band are non-compliant even if each individual lamp is approved. - End-outline marker lamps must sit "as close as possible" to the highest point of the vehicle — the letter of the law is within 400 mm of the roofline.
Switching and electrical behaviour
R48 also regulates switching logic. Position lamps must not be extinguishable independently of the headlamp. Direction indicators must flash at 90 ± 30 per minute. DRLs must switch off automatically when main-beam or dipped-beam is active. Reverse lamps must only be on when reverse gear is engaged AND the ignition is on.
A vehicle where a workshop has fitted an always-on DRL in place of a factory-switched one is not R48-compliant, even if the lamp itself is R87-approved.
How R48 applies to retrofits
R48 is part of the Whole Vehicle Type Approval (WVTA). When the vehicle left the factory it was R48-compliant. Adding or moving a lamp can invalidate that approval.
Low-risk retrofits (like-for-like replacement of a factory marker lamp with an R7-certified LED in the same position): generally no issue. Higher-risk retrofits (adding a rear fog to a trailer that didn't have one, fitting auxiliary high-beams on a cab roof): require checking the new lamp positions against R48 tables before the vehicle passes its next annual inspection.
When in doubt, ask the inspection body — but the safe habit is to match factory mounting points whenever possible.