What is the difference between the E-mark and the e-mark?

The upper-case E-mark, a letter E followed by a country number inside a circle, signals a type approval granted under a UNECE Regulation such as ECE R10 by an authority of a contracting party to the 1958 Agreement. The lower-case e-mark, a letter e followed by a number inside a rectangle, is the EU/EC type-approval mark used under EU directives and framework regulations. For automotive EMC it is the circled upper-case E-mark that is affixed. It must not be confused with the CE marking of the EU directive, which follows a separate self-declaration logic.

What exactly does ECE R10 cover?

Regulation No. 10 covers the electromagnetic compatibility of vehicles in categories L, M, N, O and T, together with the electrical and electronic sub-assemblies known as ESAs. It sets requirements for broadband and narrowband emissions, immunity to radiated fields and conducted disturbances, and tests specific to rechargeable vehicles connected to the mains. Approval is granted by a national authority and shown by an E-mark on the vehicle or the ESA.

Does ECE R10 replace the EMC Directive 2014/30 for a vehicle?

For a complete road vehicle and its ESAs, ECE R10 (taken up by Regulation (EU) 2018/858 on vehicle approval) applies, not the EMC Directive 2014/30/EU. The EMC Directive explicitly excludes vehicles and equipment already covered by type-approval legislation. A standalone electronic module sold on the market outside any vehicle context may instead fall under the ordinary EMC Directive with CE marking.

Which immunity tests does ECE R10 require?

Immunity covers exposure of the whole vehicle to radiated electromagnetic fields (under the ISO 11451 series) and exposure of ESAs on the bench (under the ISO 11452 series), plus immunity to conducted transient disturbances on the supply lines (under ISO 7637). The field levels and the performance criteria depend on the function involved and whether it is safety-related. Functions linked to vehicle control are held to the strictest criteria.

What is an ESA under ECE R10?

An ESA, electrical/electronic sub-assembly, is an electrical or electronic sub-assembly intended to be part of a vehicle, with an electrical or electronic function, that may be approved separately at the manufacturer's request. An engine control unit, a LED lighting module, an infotainment system or an on-board charger are examples of ESAs. Each ESA can carry its own E-mark once approved, then be fitted into a vehicle that is approved as a whole.

Are rechargeable electric vehicles subject to extra tests?

Yes. When a vehicle is connected to the mains in charging mode (the REESS charging coupled to the power grid mode), ECE R10 adds conducted emission requirements on the AC and DC charging ports, together with tests for harmonic current emissions and voltage fluctuations and flicker, aligned with the IEC 61000-3-2 and IEC 61000-3-3 series. These tests treat the vehicle as mains-connected equipment while it is charging.

How long does an ECE R10 approval take?

The lead time depends on the laboratory, the availability of the vehicle or the ESAs and the queue at the approval authority (technical service). A full vehicle EMC campaign, with emission, radiated and conducted immunity and, where relevant, charging-related tests, needs several weeks of laboratory time. Review of the file by the authority and issue of the certificate add administrative time. Spilma does not publish a guaranteed figure.

Is the E-mark recognised outside the European Union?

UNECE type approval is recognised by the contracting parties to the 1958 Agreement of the UN Economic Commission for Europe, which reaches well beyond the European Union and includes Japan, South Korea, Russia, Turkey and many others. An E-mark granted by a signatory authority is in principle accepted by the other contracting parties for the same Regulation. The United States and Canada are not parties to the 1958 Agreement and run their own regimes (FMVSS, FCC), distinct from ECE R10.

ECE R10: automotive EMC and the E-mark

Author Hugues Orgitello Last updated 30 May 2026 ~9 min read

Guide, automotive EMC

The electromagnetic compatibility of a road vehicle is not handled like that of a desktop appliance. A car packs dozens of electronic control units, power motors, an ignition system, a network of sensors and, increasingly, high-voltage electric traction, all within a few centimetres of radio antennas and sensitive receivers. The UNECE R10 regulation, known as ECE R10, is the framework that governs this EMC for the type approval of vehicles and their electrical and electronic sub-assemblies. This guide sets out its scope, the difference between the E-mark and the CE marking, the emission and immunity test suite, the CISPR and ISO standards it calls up, the special case of rechargeable vehicles, and the boundary with the EMC Directive 2014/30/EU.

What ECE R10 governs

Regulation No. 10 of the UN Economic Commission for Europe pursues a single objective: to ensure that vehicles and their electronic components stay electromagnetically compatible. This covers two mirror requirements, exactly as in general EMC. First, the vehicle must not emit disturbances liable to degrade radio and television reception on board or nearby, nor interfere with other equipment. Second, the vehicle and its systems must stay immune to the fields and disturbances met in use, whether a powerful radio transmitter, an electrostatic discharge or a transient on the vehicle network.

ECE R10 is a regulation adopted under the 1958 Agreement of the UNECE, which organises a mutually recognised type approval between the contracting parties. Within the European Union, it is made mandatory by Regulation Regulation (EU) 2018/858 on the approval and market surveillance of motor vehicles, which lists ECE R10 among the applicable regulatory acts. A manufacturer therefore makes no CE declaration for the EMC of a vehicle: it obtains a type approval, shown by an E-mark.

The E-mark and the CE marking

This is the most common source of confusion. Three distinct markings coexist in the European automotive world, and they do not mean the same thing.

Marking	Shape	Meaning	Framework
E-mark (upper case)	letter E + country number in a circle	type approval granted under a UNECE Regulation	1958 Agreement, Regulation (EU) 2018/858
e-mark (lower case)	letter e + number in a rectangle	EU/EC type approval under EU directives	EU directives and framework regulations
CE marking	CE logo	conformity by self-declaration to New Approach directives	EMC Directive 2014/30/EU, among others

For the EMC of a vehicle or an ESA approved under ECE R10, it is the upper-case E-mark inside a circle that is affixed. The number inside the circle identifies the country of the authority that granted the approval (for example E2 for France, E1 for Germany). A full approval number is placed alongside. The lower-case e-mark in a rectangle is, by contrast, the EU/EC mark used under EU directives, not under ECE R10.

The point to remember: a road vehicle does not carry a CE marking for its EMC. The EMC Directive 2014/30/EU excludes from its scope equipment already covered by type-approval legislation. Confusing the two markings, or affixing a CE marking where an E-mark is required, is a clear conformity error.

Scope: vehicles and ESAs

ECE R10 addresses two distinct but linked objects.

Vehicles

The regulation covers vehicles in categories L (two and three wheelers, quadricycles), M (carriage of passengers), N (carriage of goods), O (trailers) and T (agricultural tractors), wherever they contain electrical or electronic systems. Approval applies to the complete vehicle, tested in a representative configuration, engine running and systems active.

ESAs

An ESA, electrical/electronic sub-assembly, is an electrical or electronic sub-assembly intended to equip a vehicle. At the manufacturer's request, an ESA may be approved separately and carry its own E-mark. An engine management ECU, a LED lighting block, a traction inverter, an on-board charger or an infotainment module are all ESAs. Once approved, the ESA can be fitted into a vehicle without a further EMC test of that sub-assembly, which simplifies the supply chain.

The regulation also distinguishes ESAs according to whether they take part in safety-related functions, which determines the performance criteria applied during immunity testing.

The emission test suite

Emission tests check that the vehicle or the ESA does not disturb radio receivers. They divide along two fundamental distinctions: broadband versus narrowband, and radiated versus conducted emission.

Broadband emissions: disturbances appearing over a wide range of frequencies, typically produced by impulsive phenomena such as ignition or switching. At the vehicle level they are assessed under CISPR 12 (disturbances radiated to the outside of the vehicle).
Narrowband emissions: disturbances concentrated on precise frequencies, typical of oscillators, microcontrollers and switching converters. The protection of on-board receivers relies on CISPR 25, which sets limits and methods for the radiated and conducted emissions of components and modules, measured at the ports and near the on-board antennas.

At the ESA level, CISPR 25 is the central reference: it defines the severity classes (1 to 5), the measurement set-ups (LISN, antennas, cells), and the limits for protecting receivers from the LW/MW band up to the high bands. The manufacturer chooses the class according to the level of protection targeted for the vehicle's receivers.

Aspect	Vehicle level	ESA level
Emission radiated to the outside	CISPR 12	not applicable
Protection of on-board receivers	CISPR 25	CISPR 25
Broadband and narrowband	both assessed	both assessed
Conducted emission	vehicle network	LISN on supply lines

The immunity test suite

Immunity is the counterpart of emission: the vehicle must keep working correctly in a disturbed environment. ECE R10 organises these tests around three families of ISO standards.

Immunity to radiated fields

At the vehicle level, exposure to radiated electromagnetic fields follows the ISO 11451 series. The complete vehicle is placed in front of one or more antennas and subjected to fields over a wide frequency range, at levels representative of the transmitters met in use (broadcast stations, radars, mobile telephony). At the component level, the ISO 11452 series defines the bench methods: antenna, TEM cell, coupling line (stripline), bulk current injection (BCI). These tests reproduce the exposure of an isolated ESA to RF fields.

Immunity to conducted transient disturbances

The automotive network is an electrically harsh environment: inductive load dumps, cranking, microcuts. The ISO 7637 standard defines the reference transient pulses (pulses 1, 2a, 2b, 3a, 3b, and the load dump) injected on the supply lines, and the associated performance criteria. It is the automotive equivalent, but far more severe, of the electrical fast transient and surge tests of general EMC.

Electrostatic discharge

Immunity to electrostatic discharge (ESD) is also addressed, generally by reference to ISO 10605, which adapts the ESD method to automotive specifics (human body models, handling of modules in assembly and in service). The performance criteria distinguish safety-related functions from comfort functions.

The rechargeable vehicle case

Electrification has added a dimension to ECE R10. When a battery vehicle is connected to the mains in charging mode (the REESS charging coupled to the power grid mode), it behaves like mains-connected equipment and must be assessed as such. The regulation then adds:

conducted emission requirements on the AC and DC charging ports, so as not to pollute the grid and the domestic installation;
harmonic current emission tests, aligned with the logic of IEC 61000-3-2;
voltage fluctuation and flicker tests, aligned with IEC 61000-3-3.

These requirements apply only in the connected charging mode. While driving, the vehicle falls back under the ordinary emission and immunity tests. The on-board charger is the critical component here, and it is often approved as a separate ESA. For the charging chain on the infrastructure side, see the guide on IEC 61851, ISO 15118 and OCPP.

Approval procedure, step by step

The EMC type-approval process follows a fairly stable sequence, which the applicant works through with a technical service and an approval authority.

Define the scope. Decide whether it is a vehicle approval, an ESA approval, or both, and list every electrical and electronic system involved.
Choose the classes and levels. Set the targeted CISPR 25 class, the ISO 11451/11452 field levels and the applicable ISO 7637 pulses, according to the safety-related functions.
Draw up the test plan. List the emission and immunity tests, the operating modes tested, the performance criteria by function. See the test plan template.
Run the tests. In an accredited laboratory and, for the complete vehicle, in a facility able to take the vehicle (a large semi-anechoic chamber).
Compile the file. Test reports, technical descriptions, drawings, the list of ESAs and their approvals. See the technical documentation file contents.
Submit the application. To the approval authority, which reviews the file and issues the approval certificate.
Affix the E-mark. On the vehicle or the ESA, with the approval number, and ensure conformity of production (CoP).

Difference with the CE route of Directive 2014/30

The boundary between ECE R10 and the EMC Directive Directive 2014/30/EU is sharp but worth spelling out, because the two regimes treat the same physics with opposite legal logics.

Criterion	ECE R10 (E-mark)	EMC Directive 2014/30 (CE marking)
Object	automotive vehicles and ESAs	apparatus and fixed installations in general
Logic	type approval before placing on the market	self-declaration (module A)
Third party	approval authority and technical service	no notified body as a rule
Test standards	CISPR 12, CISPR 25, ISO 11451/11452, ISO 7637	EN 55032/55035 and EN 61000 series
Marking	E-mark + number	CE marking
Recognition	parties to the 1958 Agreement	the Union internal market

The EMC Directive excludes from its scope motor vehicles and their trailers already covered by approval legislation. In practice, an electronic module intended to equip a vehicle does not fall under CE marking through the EMC Directive: it follows the ECE R10 route. By contrast, the same circuit sold as a standalone product outside any vehicle context (for example a laboratory measuring instrument) will fall under the EMC Directive with CE marking. For the wider comparison between the European and American approaches, see CE versus FCC for EMC.

Place in the automotive regulatory ecosystem

ECE R10 is only one piece of the approval system. It sits alongside other requirements that the manufacturer handles in parallel.

Functional safety is covered by ISO 26262, distinct from EMC but linked: an EMC disturbance can trigger a safety event, so the safety analysis takes immunity into account. See ISO 26262, automotive functional safety.
Component quality follows the AEC-Q100 and related schemes for automotive semiconductors. See AEC-Q100 and Q101.
Defence and military vehicles apply a separate, far more severe EMC framework, described in the guide on MIL-STD-461 and 464.

Common pitfalls

Pitfall	Consequence	Good practice
Affixing a CE marking for the EMC of a vehicle	non-conformity: the E-mark is what applies	affix the E-mark with the approval number
Confusing the E-mark (circle, UNECE) with the e-mark (rectangle, EU)	incorrect marking	check the exact shape and frame required
Forgetting the charging-related tests on an EV	incomplete file for the mains-connected mode	include conducted emission, harmonics and flicker
Under-classing in CISPR 25	on-board receivers disturbed in production	choose the class by the real protection targeted
Neglecting per-function performance criteria	immunity wrongly assessed for safety functions	define the criteria function by function
Believing an approved ESA exempts the vehicle	the complete vehicle still needs approval	approve both vehicle and ESA per the scope
Ignoring conformity of production (CoP)	approval questioned after audit	maintain a documented CoP plan

Sources and references

Sources & references

UN Regulation No. 10, uniform provisions concerning the approval of vehicles with regard to electromagnetic compatibility , UNECE unece.org/transport/documents/2021/03/standards/un-regulation-no-10
Agreement concerning the adoption of harmonized technical UN Regulations (1958 Agreement) , UNECE unece.org/transport/vehicle-regulations
Regulation (EU) 2018/858 on the approval and market surveillance of motor vehicles , EUR-Lex eur-lex.europa.eu/eli/reg/2018/858/oj
CISPR 25, radio disturbance characteristics for the protection of receivers used on board vehicles , IEC webstore.iec.ch/publication/67889
CISPR 12, vehicles, boats and internal combustion engines, radio disturbance characteristics , IEC webstore.iec.ch/publication/61031
ISO 11452, road vehicles, component test methods for electrical disturbances from narrowband radiated electromagnetic energy , ISO www.iso.org/standard/74103.html
ISO 7637, road vehicles, electrical disturbances from conduction and coupling , ISO www.iso.org/standard/50925.html
Directive 2014/30/EU on electromagnetic compatibility , EUR-Lex eur-lex.europa.eu/eli/dir/2014/30/oj