LEDr Briefing

What Is ECE R37 LEDr? How R37, R.E.5 and Product Approval Fit Together

R.E.5 defines the technical category. UN R37 provides the type-approval framework. The exact bulb still needs its own approval evidence. Confusing those three levels is the source of many misleading LED retrofit claims.

Published 22 July 2026 · Prepared by Jack Liu
Quick answer

R37, R.E.5 and a product certificate are three different things

R.E.5 contains the technical specifications for named light-source categories. UN Regulation No. 37 provides the approval framework used for light-source types within its scope. A type-approval communication then applies that framework to an exact manufactured product.

That is why “R.E.5 certified” is inaccurate and “H11 LEDr exists” is not enough to prove a supplier's bulb is approved. The category, the product approval and the physical product must all match.

Regulatory roles

What R.E.5 defines and what UN R37 approves

R.E.5 is the shared category-specification library used across the UN light-source regulations. It contains category-specific dimensions, reference geometry, electrical characteristics, photometric requirements and other technical provisions. Group 5 is where LED replacement light-source categories are placed.

UN R37 deals with approval of a defined light-source type. The approval process identifies the holder, type, category, rated values, marking and supporting technical documentation. The result is tied to a specific product type, not to every aftermarket bulb with the same connector.

Think of R.E.5 as the technical target and R37 as the approval route. The certificate or approval communication is the evidence that a particular type has actually passed through that route.

Core distinction

Use three levels when reading any LEDr claim

LevelQuestionTypical evidence
CategoryDoes a standardized LED replacement specification exist?Current R.E.5 and adopted amendments
ProductHas this exact manufactured type been approved?Type-approval communication and matching marking
UseIs the product used within its approved configuration and applicable market conditions?Instructions, application scope and destination-market requirements

A claim can fail at any one of these levels. A category may exist while a supplier's product remains unapproved. A product may be approved while a distributor overstates the market scope. A valid E-mark can also be cited for the wrong regulation.

Verified H11 example

EB-H11 shows how the pieces connect

The AZMK EB-H11 is a verified H11 LED replacement example. Its UN R37 approval reference is E8*37R03/49*0106*00, with technical report CS008-26-TAC. The same electrical configuration also has a separate UN R10 EMC approval, E8*10R06/03*17720*00.

The useful point is not the number itself. It is the chain: H11 LEDr exists as a regulated category, the exact EB type has its own R37 approval, and the physical product and marking must remain connected to that approval record.

R10 is shown separately because EMC and light-source approval are different approval objects. Combining them into one vague “ECE certificate” removes the information a buyer actually needs.

Product identity

An E-mark only helps when you know what it refers to

An approval mark should be decoded against the complete document. An R10 mark supports electromagnetic-compatibility evidence. An R37 approval relates to the defined light-source type. A headlamp approval under R112 or R149 concerns a different approval object again.

For sourcing, compare the approval number, type designation, category and physical marking with the actual production sample. A related-looking SKU or a bulb sharing the same base should not inherit the approval automatically.

After approval

Type approval is not a one-time paperwork event

The approved type must remain controlled in production. Changes to LEDs, drivers, mechanical references, cooling parts, marking or manufacturing arrangements can affect whether the product still matches the approved type.

That is why change control matters to importers and brands. A certificate can remain valid while the product shipped under the same commercial name has changed. Buyers should require traceability between the approved type, current hardware revision and later production batches.

Where a change falls outside the approved definition, the approval holder must determine whether an extension, additional testing or a new approval is required.

FAQ

R37 and LEDr questions

Is R.E.5 a product certificate?

No. It contains category specifications.

Does an LEDr category approve every bulb with the same base?

No. The exact manufactured type still needs its own approval.

Is an R10 E-mark the same as R37 approval?

No. R10 covers electromagnetic compatibility; R37 covers the light-source type within its scope.

Can an approved product be changed later?

Yes, but the approval impact of the change must be assessed and controlled.

Evidence

Official sources

The public product reference used in this article is EB-H11.

About the author

Jack Liu

Jack Liu has worked in automotive LED lighting since 2011 and began designing LED automotive headlight products in 2015. Since 2017, he has concentrated on automotive lighting regulations, particularly LED replacement light sources (LEDr), approval requirements, regulatory definitions, and how product design and optical performance affect legal compliance. Drawing on hands-on product development experience and research into official UNECE and other regulatory documents, he writes to make complex automotive lighting rules clearer and more practical for manufacturers, brands, importers and technical teams.