FCC permissive changes: Class I, II, III and RED delta

Hugues Orgitello updated 7 Oct 2026 16 min read

A certified product is never frozen. Component shortages, a firmware release, a cheaper BOM, a new antenna: every change reopens the question of whether the existing authorization still covers what ships. The FCC answers with a short rule, 47 CFR 2.1043, that sorts changes into three permissive classes and a residual "new grant" bucket. Canada uses four classes in RSP-100. The EU has no class scale at all: the RED asks the manufacturer to keep series production in conformity and keep the file current, and the CRA adds its own definition of substantial modification. This guide reads each text paragraph by paragraph, lists what changed in 2025 and 2026 (the FCC Covered List rules now reach permissive changes), and corrects common wrong readings, including some that earlier versions of this page made.

The FCC rule, paragraph by paragraph

Section 2.932(a) sets the default: a new application is required whenever the design, circuitry or construction of authorized equipment changes, except as provided for permissive changes. Section 2.907(b) says a grant of certification covers units identical to the tested sample "except for permissive changes or other variations authorized" under 2.1043. Permissive changes are therefore an exception for certificated equipment (and equipment authorized under the former type acceptance and notification procedures, 2.932(b) and (c)); equipment under Supplier's Declaration of Conformity is not part of the 2.1043 scheme.

47 CFR 2.1043	What it says	Practical consequence
(a)	Changes to the basic frequency determining and stabilizing circuitry (including clock or data rates), frequency multiplication stages, basic modulator circuit or maximum power or field strength ratings need a new grant, except Class III. Other electrical or mechanical variations are allowed if they do not affect the characteristics required to be reported, or if they follow the rest of the section. Software changes that do not affect RF emissions need no filing and may be made by parties other than the grantee.	A new crystal, a different clock or data rate on the radio, a new modulator or a higher rated power is a new FCC application, not a Class II.
(b)	Three classes of permissive change, none of which may result in a change in identification. Not available for equipment prohibited under 2.903 (Covered List).	Keep the FCC ID; if the ID changes, see (d) and 2.933.
(b)(1) Class I	Modifications that do not degrade the characteristics reported and accepted at certification. No filing.	Document the evidence in your own records (2.938(a)(1) requires a record of all changes that may affect compliance).
(b)(2) Class II	Modifications that degrade the characteristics reported at initial certification; the degraded performance must still meet the minimum requirements of the rules. The grantee files complete information and test results for the characteristics affected, plus the 2.903 certification, the Covered List statement, the US agent for service of process and the 2.911(d)(7) certifications.	The modified equipment shall not be marketed under the existing grant before acknowledgement that the change is acceptable (b)(2)(ii).
(b)(3) Class III	Software changes to a software defined radio (SDR) that change frequency range, modulation type or maximum output power outside the approved parameters, or the circumstances under which it operates. Filing includes test results with the new software loaded, including RF exposure compliance. Only for equipment with no Class II change since the original approval.	The software may not be loaded, and the equipment not marketed with it, before acknowledgement (b)(3)(ii).
Note to (b)(3)	Any software change that degrades spurious and out-of-band emissions previously reported counts as a change in frequency or modulation.	It needs a Class III change or a new application.
(b)(4)	Class I and Class II changes may only be made by the holder of the grant, except as specified.	Integrators cannot file on the module maker's FCC ID.
(c)	Any other change needs a new application; the device may not be marketed until the grant is issued. The application states whether the change applies to all units (including previous production) or only units produced after authorization.	Plan the cut-over before filing.
(d)	A change in identification needs a new application: complete if reported characteristics change, abbreviated under 2.933 if they do not.	See the change in ID section below.
(e)	Amateur Radio Service equipment: specific modification rules for licensees.	Not relevant to commercial products.
(f)	For equipment other than Part 15 or Part 18, a party other than the grantee making a Class II change supplies the (b)(2) data; the equipment may not operate under the authorization before acknowledgement.	The rule's route for a Class II made by a third party; it excludes Part 15.
(g) to (l)	Broadcast transmitter specifics (stereo exciters, sub-carrier generators, subscription TV encoders, licensee modifications under 73.1690).	Not relevant to most IoT and consumer products.

The FCC publishes its interpretation in KDB 178919 (current attachment: D01 Permissive Change Policy v06), which groups guidance by antenna changes, PCB and hardware changes, enclosure changes, software changes, RF exposure and miscellaneous changes. The TCB reviewing a Class II or Class III filing applies that KDB. For the FCC framework as a whole, see the FCC pillar and the guide on FCC ID, grantee and TCB.

Antennas and modules: where most Class II filings come from

KDB 353028 D01 (antennas used with Part 15 intentional radiators) gives the antenna cases in plain terms:

• New antenna types can be added after the initial grant as a Class II permissive change, with test data for the highest gain antenna of each new type.
• An antenna that is not listed but is of the same type with equal or lower gain may be used without further approval, with exceptions: transmitters that must monitor the band they transmit on (Part 15 Subpart D unlicensed PCS, U-NII devices with DFS) can only use antennas approved with the device, and portable devices subject to SAR limits may need additional SAR testing.
• For U-NII devices with DFS, a Class II permissive change must always be filed when an antenna with lower gain than previously approved is used, even of the same type.
• If an EMC requirement allows a Class I change but the RF exposure evaluation requires Class II, the Class II change must be approved before the antenna change.
• For a certified modular transmitter, only the original grantee can request a permissive change. If the grantee will not file a Class II change to add an antenna, a new application under a different FCC ID is required.

KDB 996369 covers modular transmitters under 47 CFR 15.212. A limited module can carry a grant condition requiring the host integrator to have a Class II permissive change filed for each specific host. A host maker who wants to make permissive changes itself must either have the module grantee make them or obtain the grantee's permission to file a change in ID, after which the host maker holds its own FCC ID.

Change in identification (2.933)

A new application is required whenever the FCC ID changes, with or without a design change. A change in model or type number or trade name made under 2.924 is not a change in identification. When there is no change in design, circuitry or construction, the application need not resubmit equipment or test data unless requested, and instead attaches a statement giving:

1. the original identification;
2. the date of the original grant;
3. how the equipment with the new identification differs from the original;
4. whether the original test results remain representative and applicable;
5. the external photographs required by 2.1033(b)(10) or (c)(14), including controls and the identification label.

If the change in FCC ID also involves a design or circuitry change outside the permissive change scope, a complete application under 2.911 is needed (2.933(c)).

What changed from 2023 to 2026

Date	Text	Effect on modifications
6 February 2023	Covered List equipment authorization rules (88 FR 7624 and 7625, amending 2.932, 2.938 and 2.1043)	Permissive changes unavailable for equipment prohibited under 2.903; Class II and III filings carry the 2.903 certification and the Covered List statement.
26 December 2025	Second Report and Order, 90 FR 53227	Clarifies that modifications, including permissive changes that need no filing, are prohibited for covered equipment and for equipment that would become covered as a result of the change ("approved by rule" changes included).
13 October 2026	Third Report and Order, 91 FR 57798 (published 11 September 2026)	Any change made by a Covered List entity, or that would make the device covered equipment, needs a new grant (revised 2.1043(a)). New 2.932(f): permissive change procedures are prohibited for equipment produced by a Covered List entity. Waivers already granted for Class I and II changes to covered UAS equipment and covered routers remain in effect through 1 January 2029 according to their terms.

ISED Canada: four classes, not three

ISED does not copy the FCC scale. RSP-100 issue 12 (August 2019), section 10, says the certificate holder shall inform the certification body or ISED of any change that may affect compliance, and defines:

ISED class	Scope (RSP-100 section 10)	Notice to ISED
C1PC	Changes that do not change fundamental RF characteristics and do not degrade unwanted emissions; changes that do not change physical characteristics significantly. Also simultaneous transmission of stand-alone modules if all MPE conditions at more than 20 cm are met.	Not required unless HVIN or PMN changes
C2PC	Hardware changes affecting fundamental RF characteristics or degrading unwanted emissions; RF changes that still meet the original RSS; significant physical changes; any change of PMN or HVIN. Adding frequency bands by a hardware change is not permitted.	Required
C3PC	Firmware changes affecting RF characteristics, including firmware that enables frequency bands without hardware change.	Required, with a new and unique FVIN
C4PC	A certified module (MA or LMA) integrated into a new host that changes the reported RF emissions or RF exposure assessment.	Required, with the HMN

RSP-100 section 11 adds that every certification service application, modifications included, must show compliance with the latest issue of the applicable standards; when no new testing is needed, a statement of compliance to the latest issue is supplied. A Canadian Class II filing can therefore require a re-assessment against a newer RSS issue than the one used for the original certification. See ISED Canada radio certification and the ISED vs FCC comparison.

RED 2014/53/EU: series conformity and a living file

The RED has no permissive change classes. The texts that apply to a change are:

• Article 10(5): manufacturers ensure procedures are in place for series production to remain in conformity; changes in design or characteristics, and changes in the harmonised standards or other technical specifications used, shall be adequately taken into account.
• Article 18(2) and Article 21(2): the EU declaration of conformity and the technical documentation are continuously updated. Annex V lists the contents of the technical documentation.
• Annex III (module B), point 7: the manufacturer informs the notified body holding the EU-type examination certificate of all modifications to the approved type that may affect conformity with the essential requirements or the conditions of validity of the certificate; such modifications need additional approval as an addition to the certificate.
• Annex IV (module H), point 3.5: the manufacturer keeps the notified body informed of any intended change to the approved quality system.
• Article 10(4): technical documentation and declaration kept for 10 years after the equipment has been placed on the market.

The essential requirements a change can touch are Article 3(1)(a) (health and safety), 3(1)(b) (EMC), 3(2) (efficient use of spectrum) and, where a delegated act activates them, 3(3). Article 3(3)(d), (e) and (f) apply from 1 August 2025 under Delegated Regulation (EU) 2022/30, with EN 18031-1, -2 and -3 (CEN-CENELEC) cited with restrictions by Decision (EU) 2025/138.

The Blue Guide 2022 (section 2.1) deals with a different situation: a product changed after it has been put into service. Such a product must be considered new if its original performance, purpose or type is modified without this being foreseen in the initial risk assessment, the nature of the hazard has changed or the level of risk has increased, and it is made available again. The same three criteria apply to software updates, which otherwise count as maintenance. The person making a substantial modification becomes the manufacturer. For changes to units still being produced, the obligation is Article 10(5), not the Blue Guide test. For the RED in general, see the RED pillar.

CRA: substantial modification and security updates

Regulation (EU) 2024/2847 brings its own definitions:

• Article 3(30): a substantial modification is a change after placing on the market that affects compliance with the essential cybersecurity requirements of Annex I Part I, or modifies the intended purpose for which the product was assessed.
• Recital 39: a security update designed to decrease cybersecurity risk without modifying the intended purpose is not a substantial modification; a minor functionality update (visual changes, new pictograms or languages) generally is not either; a feature update that modifies the original intended functions, type or performance can be, whether shipped alone or bundled with a security update.
• Articles 21 and 22: an importer, distributor or other person that carries out a substantial modification and makes the product available becomes a manufacturer for the affected part (or the whole product if its cybersecurity as a whole is affected).
• Article 13(8): the support period is at least five years, unless the product is expected to be in use for less.
• Article 14: early warning of an actively exploited vulnerability or a severe incident within 24 hours, notified simultaneously to the CSIRT designated as coordinator and to ENISA through the single reporting platform.
• Articles 69 and 71: the Regulation applies from 11 December 2027; products placed on the market before that date are only caught if substantially modified from that date, but Article 14 reporting applies to all in-scope products, and has applied since 11 September 2026.

See the Cyber Resilience Act guide.

MDR 2017/745: approval of changes, and the legacy device test

For devices certified under the MDR, Annex IX section 4.10 requires approval from the notified body that issued the EU technical documentation assessment certificate for changes to the approved device that could affect safety and performance or the conditions prescribed for use; the manufacturer informs the notified body of planned changes, and the notified body decides whether a new conformity assessment is needed. Annex X section 5.2 has the equivalent for EU type-examination. Records are kept for at least 10 years after the last device has been placed on the market, 15 for implantable devices (Article 10(8)).

The "significant change" test belongs to Article 120 only: legacy devices with a certificate under Directive 90/385/EEC or 93/42/EEC may stay on the market under the transitional provisions provided there are no significant changes in the design and intended purpose. MDCG 2020-3 Rev. 1 explains that test for legacy devices. The IEC 62304 software safety class (A, B or C) sets the rigour of the software life-cycle process; it does not decide whether a change needs notified body approval. For classification, see MDR classes.

Cellular devices: PTCRB is a separate program

PTCRB certification is an industry program, not part of 47 CFR. A change to a PTCRB-certified device is handled under the program's own rules, independently of the FCC permissive change class. See the PTCRB pillar and the 3GPP RF conformance test plan.

Comparison table

Aspect	FCC 47 CFR 2.1043	ISED RSP-100	RED 2014/53/EU	MDR 2017/745
Structure	Class I, II, III; otherwise new grant	C1PC to C4PC	No classes; Article 10(5) and continuously updated file	Notified body approval of changes (Annex IX 4.10, Annex X 5.2)
No degradation	Class I, no filing	C1PC, no notice unless HVIN or PMN changes	File and declaration kept up to date	Depends on effect on safety and performance
Degraded but compliant	Class II, filing, no marketing before acknowledgement	C2PC, notice	Reassessment of the affected essential requirements; module B: addition to the certificate	Notified body approval if safety, performance or conditions of use may be affected
Software affecting RF	Class III for software defined radios only	C3PC for any firmware, new FVIN	As above	As above
Module in a new host	Per the grant conditions; Class II per host for some limited modules	C4PC	Integrator is the manufacturer of the final product	Not applicable
Identifier	FCC ID unchanged in Class I to III	Certification number unchanged; HVIN, PMN or FVIN may change	Declaration continuously updated	Certificate supplemented
Who files	Grantee only, except 2.1043(f) for non-Part 15/18	Certificate holder, via a CB or ISED	Manufacturer; notified body where module B or H applies	Manufacturer and notified body
Record keeping	1 year after marketing permanently discontinued (2.938(f))	Check RSP-100 and RSS-Gen	10 years after placing on the market (Article 10(4))	10 years after last device, 15 for implantable devices (Article 10(8))

A change control workflow that maps to the texts

1. Record the change. An engineering change request names the BOM lines, firmware version and documents affected. 2.938(a)(1) already requires a record of design changes that may affect compliance.
2. Screen against 2.1043(a) first. Frequency determining circuitry, clock or data rates, multiplication stages, modulator or rated power: stop, this is a new grant (or Class III for a software defined radio).
3. Compare against reported characteristics. Class I needs evidence of no degradation; Class II needs test results for the characteristics affected. A firmware change to channel tables, power tables or listen-before-talk timing is compared in the same way as a hardware change. KDB 353028 adds the antenna and RF exposure cases.
4. Check the Covered List position. Since 26 December 2025 the prohibition reaches changes that need no filing; from 13 October 2026 any change by a Covered List entity needs a new grant.
5. Run the parallel assessments. ISED class and latest RSS issue; RED Article 10(5) and affected essential requirements, notified body under module B or H; CRA Article 3(30) and the intended purpose; MDR Annex IX 4.10 where relevant.
6. Hold shipments where the text says so. No marketing under the FCC grant before Class II or III acknowledgement; update the EU declaration and file before the changed units are placed on the market.
7. Close with traceability. Link the change request to test reports, the TCB acknowledgement, the ISED notice, the updated declaration and the production cut-over date.

Claims the texts contradict

Common claim (including earlier versions of this page)	What the text says
"Class I means no effect on measured RF parameters"	Class I means no degradation of the characteristics reported and accepted at certification (2.1043(b)(1)). An improvement is still Class I.
"Class II covers any change affecting measured RF characteristics within the same rule sections"	Class II covers degradation that still meets the rules (2.1043(b)(2)), but changes to frequency determining circuitry, clock or data rates, modulator or rated power need a new grant (2.1043(a)).
"Permissive changes apply to Certification, SDoC and Verification"	2.1043 is about certificated equipment (and former type acceptance or notification, 2.932(b) and (c)).
"A Class II filing goes to the initial TCB"	2.1043 does not say which TCB; it says only the grantee may make Class I and II changes (b)(4).
"Class IV is industry slang for a new FCC application"	The FCC has no Class IV. C4PC is an official ISED class for module integration in a new host (RSP-100 section 10.4).
"ISED Class III mirrors the FCC SDR class"	ISED C3PC covers any firmware change affecting RF characteristics, including enabling bands, with a new FVIN (RSP-100 section 10.3).
"ISED rules are in RSS-Gen and DC-01"	Permissive change classes are in RSP-100 section 10.
"RED Article 10(9) requires conformity to be maintained"	Article 10(9) is about the copy of the declaration accompanying the equipment. Series conformity and design changes are Article 10(5).
"The RED has three essential requirements: 3.1(a), 3.1(b), 3.2, 3.3"	That is four groups; 3(3) only applies where a delegated act activates it.
"A RED change needs a new DoC with an incremented identifier"	Articles 18(2) and 21(2) require the declaration and documentation to be continuously updated; the numbering scheme is the manufacturer's choice.
"FCC records are kept five years after last manufacture"	2.938(f): one year after marketing is permanently discontinued for certified equipment, two years for other records under that section.
"MDR Article 120 governs modifications to MDR devices"	Article 120 is transitional, for legacy devices. MDR-certified devices follow Annex IX section 4.10 or Annex X section 5.2.
"The CRA requires a 24-hour disclosure to ENISA"	Article 14: early warning within 24 hours to the CSIRT designated as coordinator and to ENISA simultaneously, through the single reporting platform.
"Firmware updates are always inside the FCC conformity perimeter"	2.1043(a): software changes that do not affect RF emissions need no filing and may be made by anyone.

See also

• Component substitution rules
• EU market surveillance and Safety Gate (formerly RAPEX)
• Product recall and EU Safety Gate response procedure
• EU Declaration of Conformity (DoC): template + content
• Certification test plan: template and checklist

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Sources & references

1. 47 CFR 2.1043, changes in certificated equipment, Electronic Code of Federal Regulations www.ecfr.gov/current/title-47/chapter-I/subchapter-A/part-2/section-2.1043
2. 47 CFR 2.932, modification of equipment, Electronic Code of Federal Regulations www.ecfr.gov/current/title-47/chapter-I/subchapter-A/part-2/section-2.932
3. 47 CFR 2.933, change in identification of equipment, Electronic Code of Federal Regulations www.ecfr.gov/current/title-47/chapter-I/subchapter-A/part-2/section-2.933
4. 47 CFR 2.938, retention of records, Electronic Code of Federal Regulations www.ecfr.gov/current/title-47/chapter-I/subchapter-A/part-2/section-2.938
5. 47 CFR 2.909, responsible party, Electronic Code of Federal Regulations www.ecfr.gov/current/title-47/chapter-I/subchapter-A/part-2/section-2.909
6. FCC Third Report and Order, 91 FR 57798 (11 September 2026), effective 13 October 2026, Federal Register www.federalregister.gov/documents/2026/09/11/2026-18535/protecting-against-national-security-threats-to-the-communications-supply-chain-through-the
7. FCC Second Report and Order, 90 FR 53227 (25 November 2025), effective 26 December 2025, Federal Register www.federalregister.gov/documents/2025/11/25/2025-21001/protecting-against-national-security-threats-to-the-communications-supply-chain-through-the
8. FCC KDB 178919, Section 2.1043 permissive changes (D01 Permissive Change Policy v06), Federal Communications Commission apps.fcc.gov/oetcf/kdb/forms/FTSSearchResultPage.cfm?id=33013&switch=P
9. FCC KDB 996369, modules and module certification (Section 15.212), Federal Communications Commission apps.fcc.gov/oetcf/kdb/forms/FTSSearchResultPage.cfm?id=44637&switch=P
10. FCC KDB 353028, antennas used with Part 15 intentional radiators, Federal Communications Commission apps.fcc.gov/oetcf/kdb/forms/FTSSearchResultPage.cfm?id=39060&switch=P
11. RSP-100 issue 12, Certification of Radio Apparatus and Broadcasting Equipment, section 10, Innovation, Science and Economic Development Canada ised-isde.canada.ca/site/spectrum-management-telecommunications/en/devices-and-equipment/radio-standards-procedures-rsp/rsp-100-certification-radio-apparatus-and-broadcasting-equipment
12. Directive 2014/53/EU (RED), Articles 10, 18, 21 and Annexes III and IV, EUR-Lex eur-lex.europa.eu/eli/dir/2014/53/oj
13. Blue Guide on the implementation of EU product rules 2022, section 2.1, European Commission eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:52022XC0629(04)
14. Regulation (EU) 2024/2847 (Cyber Resilience Act), Articles 3(30), 13, 14, 22, 69 and 71, EUR-Lex eur-lex.europa.eu/eli/reg/2024/2847/oj
15. Regulation 2017/745 (MDR), Article 120 and Annexes IX and X, EUR-Lex eur-lex.europa.eu/eli/reg/2017/745/oj
16. MDCG endorsed guidance index, including MDCG 2020-3 Rev. 1 on significant changes for legacy devices, Medical Device Coordination Group health.ec.europa.eu/medical-devices-sector/new-regulations/guidance-mdcg-endorsed-documents-and-other-guidance_en