CE vs FCC: EMC comparison for electronics

Hugues Orgitello updated 7 Oct 2026 16 min read

Designing the same product for the European Union and the United States is not a matter of doubling the test campaign. The two EMC regimes share a CISPR heritage: the conducted mains limits are the same numbers on both sides, and Part 15 even accepts CISPR 22 radiated limits as an alternative. They still diverge on points that are expensive when found late: which distance each limit is written for, which class the product belongs to, and immunity, which only the EU requires. This guide goes back to the texts as they stand on October 7, 2026 (Directive 2014/30/EU, the RED, 47 CFR Parts 2 and 15, CISPR 32 and the ANSI C63 editions the FCC incorporates), puts the limits side by side at the same distance, and lists the common readings the texts contradict.

Regulatory frames: two architectures, one objective

Both regimes aim to keep equipment from disturbing radio services and each other, but the legal architecture is different.

EU side: essential requirements plus harmonised standards

Directive 2014/30/EU, applicable since April 20, 2016, sets two essential requirements in Annex I, point 1: the disturbance generated must not exceed the level above which other equipment cannot operate as intended (emissions), and the apparatus must have a level of immunity that lets it operate without unacceptable degradation (immunity). The directive contains no numbers. Harmonised standards cited in the OJEU turn those requirements into limits and give the presumption of conformity. For multimedia equipment, the cited editions are EN 55032:2015 + A11:2020 (emissions) and EN 55035:2017 + A11:2020 (immunity). See CE harmonised standards and the EMC Directive.

For radio equipment (Wi-Fi, BLE, cellular), the EMC Directive does not apply separately: it excludes equipment covered by Directive 1999/5/EC (Article 2(2)(a)), a reference read as the RED, Directive 2014/53/EU. EMC is then Article 3(1)(b) of the RED, covered by the specific parts of the EN 301 489 series. See RED standards.

US side: limits written into 47 CFR

The FCC writes the limits into the rules. For digital devices (unintentional radiators), 47 CFR Part 15 Subpart B sets the conducted limits (15.107) and radiated limits (15.109). Unlicensed transmitters are in Subpart C (for example 15.247 and 15.249) and Subpart E (15.407 for U-NII). Cellular bands fall under other rule Parts, such as 22, 24 and 27.

The measurement methods are standards incorporated by reference: ANSI C63.4-2014 for unintentional radiators (15.31(a)(4)) and ANSI C63.10-2020 for unlicensed transmitters (15.31(a)(3)). Since October 30, 2025, ANSI C63.10-2013 is no longer accepted for new measurements (15.37(s)). Both standards are published by IEEE.

Authorization routes

Aspect	EU	US
Source of limits	Harmonised standard (EN 55032 for multimedia equipment)	Rule text: 47 CFR 15.107 and 15.109
Test method	CISPR 16 series, referenced by CISPR 32	ANSI C63.4-2014 (15.31(a)(4)); ANSI C63.10-2020 for unlicensed transmitters
Legal effect of the standard	Presumption of conformity with the essential requirements	Compliance with the rule itself; 15.109(g) allows the CISPR 22 (third edition) radiated limits as an alternative
Procedure for a digital device without radio	Internal production control (Annex II), or EU-type examination (Annex III), at the manufacturer's choice (Article 14)	SDoC or certification, for Class A and Class B digital devices alike (15.101(a))
Procedure for a radio product	RED: internal production control unless Article 17(4) requires a notified body	Certification by a TCB for intentional radiators (15.201(b))
Immunity	Essential requirement (Annex I, point 1(b))	No immunity test in Part 15
Who may test	Not specified for internal production control	Certification: accredited and recognised laboratory (2.948(a)); SDoC: no accreditation (2.906(a)(1))

Measurement methods: where divergence starts

Distance: which limit is written for which distance

The common shortcut "CISPR at 10 m, FCC at 3 m" is half right.

Limit table	Distances in the text
CISPR 32 Class A and Class B, 30 MHz to 1 GHz (OATS or SAC)	Both 10 m and 3 m rows; the 3 m values are 10 dB higher
CISPR 32, 1 to 6 GHz	3 m, free-space conditions
FCC Class B, 15.109(a)	3 m
FCC Class A, 15.109(b)	10 m

The FCC lets the lab measure at another distance at or above 30 MHz, provided the measurement is not made in the near field and the signal can still be detected, and not beyond 30 m unless shorter distances are impractical. The result is then extrapolated to the specified distance with 20 dB per decade (15.31(f)(1)). From 10 m to 3 m that is 20 log(10/3) = 10.5 dB. CISPR 32 does not extrapolate: it prints its own 3 m rows, 10 dB above the 10 m ones. Detail on test sites and validation is in radiated emissions and EMC chamber types.

Detectors and bandwidths

The detector split is the same on both sides.

Range	CISPR 32	FCC Part 15 (15.35)
Conducted emissions, 150 kHz to 30 MHz	Quasi-peak and average limits	Quasi-peak and average limits (15.107)
Radiated, 30 MHz to 1 GHz	Quasi-peak	Quasi-peak (15.35(a))
Radiated, above 1 GHz	Peak and average, 1 MHz bandwidth	Average with a 1 MHz minimum resolution bandwidth, peak capped 20 dB above the average limit (15.35(b))

At or below 1000 MHz, 15.35(a) lets the responsible party use a peak detector instead of quasi-peak, at the same bandwidth. For any signal the peak reading is never lower than the quasi-peak reading, so a pass with the peak detector is also a pass in quasi-peak; the reverse is not true.

How high the radiated test goes

Both texts tie the upper frequency to the highest frequency generated or used in the device, with the same breakpoints up to 1 GHz.

Highest internal frequency	CISPR 32 Table 1	47 CFR 15.33(b)(1)
Below 1.705 MHz	1 GHz	30 MHz
1.705 to 108 MHz	1 GHz	1000 MHz
108 to 500 MHz	2 GHz	2000 MHz
500 MHz to 1 GHz	5 GHz	5000 MHz
Above 1 GHz	5 times the highest frequency, or 6 GHz, whichever is lower	5th harmonic, or 40 GHz, whichever is lower

Emission limits side by side

Conducted emissions on the AC mains (150 kHz to 30 MHz)

Band	Class B (CISPR 32 Table A.10 and 15.107(a))	Class A (CISPR 32 Table A.9 and 15.107(b))
0.15 to 0.5 MHz	66 to 56 dB(µV) QP, 56 to 46 dB(µV) AVG, decreasing with the logarithm of frequency	79 dB(µV) QP, 66 dB(µV) AVG
0.5 to 5 MHz	56 dB(µV) QP, 46 dB(µV) AVG	73 dB(µV) QP, 60 dB(µV) AVG
5 to 30 MHz	60 dB(µV) QP, 50 dB(µV) AVG	73 dB(µV) QP, 60 dB(µV) AVG

The numbers are the same in both regimes because the FCC adopted the CISPR 22 conducted limits and CISPR 32 kept them. Both use a 50 µH / 50 Ω artificial mains network (LISN). A battery-only device is exempt in the US unless it can operate while connected to the AC line, for example while charging (15.107(d)). CISPR 32 also has conducted limits for wired network ports (Tables A.11 to A.13) that Part 15 does not have. See conducted emissions.

Radiated emissions, Class B, compared at both distances

FCC values are 20 log of the µV/m figures in 15.109(a). The left part compares at 10 m, with the FCC limit extrapolated by 15.31(f)(1); the right part compares at 3 m, with CISPR 32 using its own 3 m rows.

Band	FCC at 10 m (extrapolated)	CISPR 32 at 10 m	FCC at 3 m (15.109(a))	CISPR 32 at 3 m	Tighter limit
30 to 88 MHz	29.5 dB(µV/m)	30 dB(µV/m)	40.0 dB(µV/m)	40 dB(µV/m)	FCC by 0.5 dB at 10 m; equal at 3 m
88 to 216 MHz	33.0	30	43.5	40	CISPR by 3 to 3.5 dB
216 to 230 MHz	35.5	30	46.0	40	CISPR by 5.5 to 6 dB
230 to 960 MHz	35.5	37	46.0	47	FCC by 1 to 1.5 dB
960 MHz to 1 GHz	43.5	37	54.0	47	CISPR by 6.5 to 7 dB
1 to 3 GHz, average (peak)			54 (74)	50 (70)	CISPR by 4 dB
3 to 6 GHz, average (peak)			54 (74)	54 (74)	Equal

Sources: CISPR 32:2015 Tables A.4 and A.5; 47 CFR 15.109(a), 15.35. Below 1 GHz all values are quasi-peak.

Two readings follow. Neither regime is uniformly stricter, so a product sold in both markets designs to the lower limit in each band. And the conclusion can move by half a decibel depending on the conversion used (the FCC 10.5 dB extrapolation against the CISPR 10 dB step), which matters only for a result sitting right at the limit.

For Class A, both regimes write the limit at 10 m. FCC 15.109(b) gives 39.1 dB(µV/m) from 30 to 88 MHz, 43.5 from 88 to 216 MHz, 46.4 from 216 to 960 MHz and 49.5 above 960 MHz; CISPR 32 Class A gives 40 dB(µV/m) from 30 to 230 MHz and 47 from 230 MHz to 1 GHz. The FCC is tighter from 30 to 88 MHz and from 230 to 960 MHz, CISPR 32 elsewhere below 1 GHz.

The CISPR 22 alternative in Part 15

15.109(g) lets a digital device show compliance with the radiated limits of the third edition of CISPR 22 instead of 15.109(a) or (b). The Part 15 test procedure still applies (15.109(g)(1)), and above 1000 MHz compliance is still shown against 15.109(a) or (b), extrapolated to the CISPR 22 distance if needed: the rule gives 150 µV/m at 10 m for Class B as the example (15.109(g)(2)). The option does not let a lab submit a CISPR 32 report as is.

Class A and Class B: who decides and what the user is told

FCC side

The class follows how the device is marketed. 15.3(h) defines a Class A digital device as one "marketed for use in a commercial, industrial or business environment, exclusive of a device which is marketed for use by the general public or is intended to be used in the home". 15.3(i) defines Class B as one marketed for use in a residential environment, giving personal computers and calculators as examples.

Both classes carry a user statement in the manual, "the following or similar statement, placed in a prominent location" (15.105). The Class A statement (15.105(a)) ends: "Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense." The Class B statement (15.105(b)) says there is no guarantee interference will not occur and lists measures the user can try. The statements do not change the authorization route: Class A and Class B digital devices both use SDoC or certification (15.101(a)).

EU side

CISPR 32 assigns Class B to equipment intended primarily for the residential environment and Class A to the rest, and requires Class A equipment to carry a warning in its user information that it may cause radio interference in a residential environment. The directive adds its own duty: apparatus for which compliance with the essential requirements "is not ensured in residential areas shall be accompanied by a clear indication of such restriction of use, where appropriate also on the packaging" (Article 18(2) of Directive 2014/30/EU). A product that can be used in homes is assessed against Class B. See CE pitfalls.

Immunity: the structural asymmetry

What the FCC requires

Part 15 contains no immunity test. The statement that a Part 15 device "must accept any interference received, including interference that may cause undesired operation" (15.19(a)(3)) is a condition of operation, not a test.

What the EU requires

Immunity is an essential requirement (Annex I, point 1(b)). Multimedia equipment shows it with EN 55035; other equipment with the generic EN 61000-6-1 (residential, commercial and light industrial) or EN 61000-6-2 (industrial), using the basic EN 61000-4-x methods. Levels for the AC power port in the cited EN 61000-6-1:2007:

Phenomenon	Method	EN 61000-6-1:2007 level	Criterion
Electrostatic discharge	EN 61000-4-2	4 kV contact, 8 kV air	B
Radiated RF field, 80 % AM 1 kHz	EN 61000-4-3	3 V/m (80 to 1 000 MHz), 3 V/m (1.4 to 2.0 GHz), 1 V/m (2.0 to 2.7 GHz)	A
Fast transients (burst), AC power	EN 61000-4-4	1 kV, 5 kHz	B
Surge, AC power	EN 61000-4-5	2 kV line-to-earth, 1 kV line-to-line	B
Conducted RF, 0.15 to 80 MHz	EN 61000-4-6	3 V	A
Voltage dips and interruptions	EN 61000-4-11	0 % for ½ and 1 cycle (B), 70 % for 25/30 cycles (C), interruption 250/300 cycles (C)	B or C

Industrial levels, signal ports and the EN 55035 tables are on CE tests. A board designed only against Part 15 limits has never been checked against any of these phenomena, which is why a US-first product should go through immunity pre-tests before the EU campaign.

Working on immunity diagnostics for a product originally designed for the US market only for a real product? AESTECHNO can audit your design and certification plan. Get in touch

Radio equipment: how each side splits the work

EU: RED Article 3(1)(b)

The RED list cites the specific parts of the EN 301 489 series, used with the common part EN 301 489-1, which is not itself cited. For Wi-Fi and Bluetooth the part is EN 301 489-17 (cited version V3.3.1); for cellular user equipment EN 301 489-52. The common part defines radio-specific performance criteria and test conditions. Spectrum use is a separate requirement, Article 3(2), for example EN 300 328 V2.2.2 at 2.4 GHz.

US: one device, two sets of rules

• The digital circuitry (clocks, processor, power supply) is an unintentional radiator: 15.107 and 15.109, measured to ANSI C63.4-2014.
• The transmitter is an intentional radiator: for example 15.247 at 2.4 GHz or 15.407 for U-NII, with 15.207 for its AC line conducted emissions, measured to ANSI C63.10-2020.

For a device that is both, 15.33(a)(5) sets the upper test frequency as the higher of the transmitter range and the digital-device range. KDB publications give the FCC interpretation for cases such as modules and multiple transmitters. See FCC Parts and FCC tests.

Test plan for a dual-market Wi-Fi/BLE product

Requirement	EU	US
Emissions of the digital part	EN 301 489-1 and -17 (RED 3(1)(b))	15.107, 15.109 with ANSI C63.4-2014
Immunity	EN 301 489-1 and -17	None
Spectrum and transmitter emissions	EN 300 328 (RED 3(2))	15.247, 15.209, 15.205 with ANSI C63.10-2020
Conformity route	RED Article 17	Certification by a TCB (15.201(b))

Writing one test plan that names, for each test, the clause of each standard it serves is what lets the lab run shared set-ups once.

Laboratories and the EU-US MRA

The Agreement on mutual recognition between the European Community and the United States was signed in London on May 18, 1998 (OJ L 31, February 4, 1999). Its EMC sectoral annex covers the EMC Directive on the EU side and 47 CFR Parts 15 and 18 on the US side, and lets conformity assessment bodies of one party test and certify to the other party's requirements. EU bodies are designated by the EU authorities, and US bodies by the US authorities named in the annex (NIST, FCC, FAA).

What that means in practice:

• FCC certification needs a laboratory accredited to ISO/IEC 17025 by a body recognised by the FCC and recognised by the Commission (2.948(a) and (e)). A laboratory outside the US is accepted if designated by a foreign designating authority and recognised by the Commission under an MRA, or, where no MRA exists, accredited by a body recognised under 2.949 (2.948(f)).
• FCC SDoC needs no accredited laboratory; the facility only must not be owned, controlled or directed by a prohibited entity (2.906(a)(1), since September 8, 2025).
• EU internal production control asks for test reports without saying who performs the tests. The MRA matters on the EU side only where a notified body is involved, such as EU-type examination.

The MRA does not merge the files: CE marking and an EU declaration stay on one side, an FCC grant or SDoC on the other. See EU and US dual certification and getting started.

Dated changes that affect a dual campaign

Date	Change	Source
May 18, 1998	EU-US MRA signed, with EMC and telecommunication sectoral annexes	OJ L 31, February 4, 1999
April 20, 2016	Directive 2014/30/EU applies; Directive 2004/108/EC repealed	Articles 44 to 46
March 5, 2017	EN 55022 (CISPR 22) loses presumption in the EU; EN 55032 replaces it	OJ C 14, January 16, 2015
September 16, 2022	EN 55024 leaves the EMC list; EN 55035 is the multimedia immunity standard	EMC Directive list of harmonised standards
October 30, 2023	FCC incorporates ANSI C63.10-2020 with a two-year transition and ISO/IEC 17025:2017 for accreditation	FCC 23-14, 88 FR 67108
September 8, 2025	SDoC testing barred at facilities owned or controlled by prohibited entities	FCC 25-27, 90 FR 38045
October 30, 2025	Only ANSI C63.10-2020 accepted for new unlicensed transmitter measurements	15.31(a)(3), 15.37(s)

Claims the texts contradict

Claim	What the texts say
"The FCC measures at 3 m across nearly all of Part 15" (this page said so before October 2026)	Class B limits are at 3 m (15.109(a)) but Class A limits are at 10 m (15.109(b)). CISPR 32 prints both 10 m and 3 m rows.
"Above 230 MHz CISPR becomes the tighter regime" (this page, while its own table showed 47.5 against 46)	From 230 to 960 MHz the FCC Class B limit is tighter by 1 dB at 3 m (46 against 47). CISPR 32 is tighter from 88 to 230 MHz and from 960 MHz to 3 GHz.
"CISPR scaled to 3 m is 40.5 and 47.5 dB(µV/m)" (this page)	CISPR 32 gives its own 3 m limits, 10 dB above the 10 m ones: 40 and 47 dB(µV/m). The 10.5 dB figure is the FCC extrapolation factor of 15.31(f)(1).
"FCC quasi-peak applies only to conducted emissions" (this page)	15.35(a) bases all limits at or below 1000 MHz, conducted and radiated, on the CISPR quasi-peak detector.
"Measuring in peak gives a false comfort margin; pre-test in QP" (this page)	The peak reading is never lower than the quasi-peak reading. Peak gives a pessimistic margin, which is why 15.35(a) accepts it in place of quasi-peak.
"The FCC allows 10 m measurements under waivers (15.31(f)(1))" (this page)	15.31(f)(1) is a general permission, not a waiver: another distance is allowed at or above 30 MHz, with extrapolation at 20 dB per decade.
"The Class A warning wording is dictated by 15.105(a)" (this page)	15.105 asks for "the following or similar statement", and Class B devices have their own statement in 15.105(b).
"The EU relies on the use environment, not on a formal user warning" (this page)	Article 18(2) of Directive 2014/30/EU requires a clear indication of the restriction of use for apparatus not compliant in residential areas, and CISPR 32 requires a Class A warning.
"An EU lab must be designated by the FCC" (this page)	Under the MRA, EU bodies are designated by EU authorities and recognised by the Commission (2.948(f)). The FCC is a designating authority for US bodies.
"A dual ILAC + FCC-MRA lab saves 25 to 30 %" and fixed budgets per strategy (this page)	No text gives such figures. They were removed.
"EN 61000-4-3 residential level is 3 V/m from 80 MHz to 6 GHz" (this page)	The cited EN 61000-6-1:2007 sets 3 V/m from 80 to 1 000 MHz and 1.4 to 2.0 GHz, and 1 V/m from 2.0 to 2.7 GHz.

Common pitfalls in dual EMC certification

1. Comparing limits at different distances. Put every limit at one distance first, and state which conversion is used (15.31(f)(1) for the FCC, the CISPR 32 3 m rows for the EU).
2. Forgetting immunity when coming from the US market. Part 15 never tested ESD, burst, surge or RF immunity; the EU campaign does.
3. Stopping the radiated scan at 1 GHz. A product with an internal frequency above 108 MHz is tested higher under both CISPR 32 Table 1 and 15.33(b)(1).
4. Choosing Class A for a product sold to the public. In the US the class follows the marketing (15.3(h)); in the EU, a product that can be used in homes is assessed against Class B and any residential restriction must be stated (Article 18(2)).
5. Assuming CISPR 22 compliance is enough for the FCC. 15.109(g) keeps the Part 15 test procedure and the 15.109 limits above 1 GHz.
6. Using an old ANSI C63.10 edition. Since October 30, 2025, only C63.10-2020 is accepted for unlicensed transmitters.

See also FCC pitfalls and CE pitfalls for the per-regime detail.

Key takeaways

• Immunity is EU only. Part 15 has no immunity test; the EMC Directive makes it an essential requirement.
• Conducted mains limits are identical in CISPR 32 and 15.107, Class A and Class B.
• Radiated limits differ band by band. At 3 m, the FCC is tighter from 230 to 960 MHz, CISPR 32 from 88 to 230 MHz and from 960 MHz to 3 GHz.
• FCC Class A is at 10 m, Class B at 3 m. Other distances are extrapolated at 20 dB per decade (15.31(f)(1)).
• Laboratory rules depend on the route. Accredited and recognised lab for FCC certification, none required for SDoC or EU internal production control.

For implementation on the EU side, see CE tests. On the US side, see FCC tests and FCC scope.

Working on the EMC test plan for a product targeting EU and US for a real product? AESTECHNO can audit your design and certification plan. Get in touch

Sources & references

1. CISPR 32:2015+A1:2019: Multimedia equipment, emission requirements, IEC webstore.iec.ch/publication/22046
2. ANSI C63.4-2014: American National Standard for methods of measurement of radio-noise emissions, IEEE / ANSI standards.ieee.org/ieee/C63.4/5841/
3. ANSI C63.10-2020: Procedures for compliance testing of unlicensed wireless devices, IEEE / ANSI standards.ieee.org/ieee/C63.10/10445/
4. 47 CFR Part 15: Radio frequency devices, FCC (eCFR) www.ecfr.gov/current/title-47/chapter-I/subchapter-A/part-15
5. 47 CFR 15.109: Radiated emission limits, FCC (eCFR) www.ecfr.gov/current/title-47/part-15/section-15.109
6. 47 CFR 15.31: Measurement standards (distance extrapolation in 15.31(f)(1)), FCC (eCFR) www.ecfr.gov/current/title-47/part-15/section-15.31
7. 47 CFR 15.105: Information to the user, FCC (eCFR) www.ecfr.gov/current/title-47/part-15/section-15.105
8. 47 CFR 2.948: Measurement facilities, FCC (eCFR) www.ecfr.gov/current/title-47/part-2/section-2.948
9. Directive 2014/30/EU on electromagnetic compatibility, EUR-Lex eur-lex.europa.eu/eli/dir/2014/30/oj
10. Directive 2014/53/EU on radio equipment, EUR-Lex eur-lex.europa.eu/eli/dir/2014/53/oj
11. Agreement on mutual recognition between the European Community and the United States of America (OJ L 31, 4.2.1999), EUR-Lex eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:21999A0204(01)