What is the difference between SDoC and Certification under FCC rules?

They are the two equipment authorization procedures in 47 CFR Part 2 Subpart J. SDoC (Supplier's Declaration of Conformity) is a self-declaration the responsible party signs after compliance testing, used mainly for unintentional radiators under Part 15 Subpart B. Certification is a third-party procedure where a TCB reviews the test report and issues an FCC ID, required for intentional radiators (Wi-Fi, Bluetooth, cellular and similar transmitters).

How do I get a Grantee Code?

You first register for an FRN (FCC Registration Number) in the FCC CORES system, then apply for a Grantee Code through the Equipment Authorization System. The Grantee Code is a three to five character alphanumeric prefix unique to your company, and a fee applies. Once assigned, it is permanent and forms the first part of every FCC ID you obtain.

What does an FCC ID actually consist of?

An FCC ID has two parts joined together: the Grantee Code (the first three to five characters, identifying the company) and the Equipment Product Code (the remaining characters, chosen by the grantee to identify that specific product). For example, in a hypothetical ID the prefix identifies the company and the suffix identifies the model. The full ID must appear on the device label or as an e-label.

Do I need a TCB, or can I deal with the FCC directly?

For Certification, you must use a TCB. The FCC delegated almost all certification grants to accredited Telecommunication Certification Bodies; the FCC itself no longer issues routine grants. For SDoC there is no TCB grant at all, you test, document and declare. A TCB only enters the picture on the Certification path.

What is the difference between Single and Limited Modular Approval?

Single Modular Approval means a radio module meets all eight modular requirements (shielding, buffered I/O, its own power regulation, antenna and so on) and can be integrated into any host with minimal restrictions. Limited Modular Approval is granted when one or more of those conditions are met by the host instead; the grant then carries conditions the integrator must respect, documented in the grant and the module's integration manual.

Does an FCC ID transfer to ISED Canada automatically?

No. ISED Canada issues its own certification and its own identifier (the IC number). The test data overlaps heavily, so a single test campaign often serves both, and many TCBs are also ISED-recognized Certification Bodies, but the grants are separate filings. See the ISED Canada guide for the parallel process.

Where can I check whether a module is genuinely certified?

Use the FCC ID search in the Equipment Authorization System. Entering the Grantee Code and Product Code returns the grant, the test report, the photos, the user manual and the grant conditions. This is how an integrator confirms a purchased module is really certified and reads the conditions attached to a modular grant.

FCC ID, Grantee Code & TCB: equipment authorization

Author Hugues Orgitello Last updated 28 May 2026 ~11 min read

Guide · FCC equipment authorization mechanics

Before an electronic product can be marketed in the United States, it must clear FCC equipment authorization. Two procedures exist, and the right one depends on whether the device deliberately emits radio energy. One is a self-declaration the manufacturer signs; the other ends with a federal identifier, the FCC ID, granted through a third party called a TCB. This page explains the mechanics, how to obtain a Grantee Code, how an FCC ID is built, what a TCB actually does, how labeling and modular approval work, and how all of this lines up with ISED Canada.

Two procedures, one rulebook

The rules live in 47 CFR Part 2 Subpart J, the part of the Code of Federal Regulations that codifies equipment authorization. Subpart J defines exactly two procedures for placing a device on the US market:

SDoC (Supplier's Declaration of Conformity), a self-declaration the responsible party makes after the product has been tested against the applicable rules.
Certification, a third-party procedure in which a TCB reviews the test evidence and issues an FCC ID.

Which one applies is not a free choice. It is dictated by how the device interacts with the radio spectrum, the same logic that drives the US side of the SDoC versus Certification split discussed in self-declaration vs Notified Body.

Unintentional vs intentional radiators

The FCC sorts devices by how they emit radio-frequency energy.

Device class	Definition	Procedure	Typical examples
Unintentional radiator	Generates RF energy internally but does not intend to radiate it (digital logic, clocks, switching supplies)	SDoC (Part 15 Subpart B)	Laptops, monitors, most appliances with a microcontroller
Intentional radiator	Deliberately generates and emits RF energy	Certification	Wi-Fi, Bluetooth, cellular, sub-GHz, UWB transmitters
Incidental radiator	Not designed to generate RF but may produce it (motors)	No authorization, operating conditions only	Electric motors, mechanical switches

A connected product almost always contains both: a digital section that is an unintentional radiator and a radio that is an intentional radiator. In that case the intentional radiator drives the procedure, the whole device is Certified, and the unintentional-radiator emissions are assessed inside the same certification. See the FCC procedure and the FCC pillar for the full route.

What SDoC requires

SDoC is the lighter path, but it is not a free pass. The responsible party (a US-located entity) must:

Have the product tested for compliance with the applicable Part 15 limits, using an accredited ISO/IEC 17025 laboratory where the rules call for it.
Compile the test report and supporting documentation, kept on file.
Produce a compliance information statement that names the responsible party, gives a US address or phone or internet contact, and identifies the product.
Apply the required labeling and ship the statement with the product.

There is no FCC ID under SDoC and no TCB. The declaration carries the legal weight, and market surveillance can demand the file at any time.

Identity: FRN, Grantee Code, FCC ID

The Certification path produces a permanent identity for the company and a unique identifier for each product. Three artifacts are involved, and they nest inside one another.

Step 1, the FRN

Everything starts with an FRN (FCC Registration Number), a ten-digit number that identifies your business to the FCC. You obtain it for free by registering in CORES (the Commission Registration System). The FRN is the account under which fees are paid and filings are made; it is not specific to equipment, the same FRN serves all your dealings with the FCC.

Step 2, the Grantee Code

To obtain FCC IDs you then apply for a Grantee Code through the Equipment Authorization System. The Grantee Code is a short alphanumeric prefix, three to five characters, assigned uniquely to your company. A fee applies to the assignment. Key properties:

It is permanent: once assigned, it stays with your company.
It is company-wide: one Grantee Code serves every product you certify.
It becomes the first segment of every FCC ID you create.

A company therefore registers a Grantee Code once, then reuses it across its entire portfolio.

Step 3, the FCC ID

An FCC ID is built from two concatenated parts:

Segment	Source	Length	Meaning
Grantee Code	Assigned by the FCC	3 to 5 characters	Identifies the company (the grantee)
Equipment Product Code	Chosen by the grantee	Remaining characters	Identifies the specific product

The grantee picks the Product Code freely within the allowed character set, so it can encode an internal model reference. The two parts joined together form the FCC ID that the TCB grants and that must appear on the product. Because the Grantee Code is fixed, all of a company's products share the same FCC ID prefix, which is why an FCC ID prefix can be traced back to a manufacturer.

The role of the TCB

A TCB (Telecommunication Certification Body) is an accredited organization the FCC has authorized to grant certifications on its behalf. The FCC delegated routine certification to TCBs years ago; today the Commission itself does not issue ordinary equipment certifications, the TCBs do. This is the same delegated-authority model that the conformity assessment bodies and accreditation guide describes for accredited third parties generally.

A TCB does the following:

Reviews the test report from the accredited lab against the applicable FCC rules and the relevant KDB guidance.
Checks the photographs, schematics, the user manual and the labeling.
Verifies that the SDoC-style declaration is not being misused on a device that actually needs Certification.
Issues the grant of equipment authorization, which carries the FCC ID and any conditions.
Files the grant into the FCC's database, where it becomes publicly searchable.

The TCB is not the test lab, although some organizations operate both functions under separate accreditations. Testing is performed by an ISO/IEC 17025 accredited laboratory; the TCB performs the conformity assessment and issues the grant.

TCB scope and KDB guidance

A TCB may only grant within its accreditation scope. Some device categories, or novel technologies the FCC has not yet routinized, are placed on a Permit-But-Ask list: the TCB must consult the FCC laboratory before granting. The OET Knowledge Database (KDB) is where the FCC publishes the procedures, the Permit-But-Ask list and the technical interpretations a TCB must follow. Reading the relevant KDB publications before testing avoids the most common cause of a stalled grant.

The equipment authorization database

Every Certification grant is published in the FCC's public database, historically the OET database and now the Equipment Authorization System. This is one of the most useful free tools in the field.

Using FCC ID search, you enter a Grantee Code and a Product Code and retrieve:

the grant of authorization itself (bands, maximum power, antenna gain, grant conditions);
the full test report;
internal and external photographs;
the user manual;
the labeling exhibit and the block diagram.

This database is how an integrator confirms that a purchased radio module is genuinely certified, reads the grant conditions attached to a modular approval, and verifies the antenna types and gains the module is allowed to use. It is also how market surveillance and competitors verify a product. Treat the public database as part of your due diligence on every module you design in.

A common early-stage check is to pull the grant for each candidate module before committing to a design, comparing the certified bands, the maximum conducted power, the antenna gain ceiling and the listed grant conditions. A module that is certified only with a specific antenna, or only as a Limited Modular Approval, narrows your host options before you have drawn a single trace. Doing this lookup at selection time, rather than after layout, is one of the cheapest risk reductions available in an FCC project.

Labeling rules

The label is where authorization becomes visible on the product, and it is a frequent source of non-conformity.

Authorization	What the label must show
Certification	The full FCC ID, in the form the grant specifies, legible and permanent
SDoC	No FCC ID; the compliance information statement and required text, with the responsible party's US contact

Practical rules that catch people out:

The FCC ID must be visible. If the device is too small for a physical label, the ID may be placed on the packaging and in the manual, subject to the FCC's small-device provisions.
E-labeling is permitted: the FCC ID can be displayed electronically on a screen the user can access (for example in a settings menu), provided the rules on accessibility and on a physical fallback are met.
Modular grants require the host to carry a statement such as "Contains FCC ID: [module ID]" when the module's own ID is not visible on the finished product.
The compliance statement under SDoC must name a responsible party physically located in the United States; a non-US manufacturer needs a US-based responsible party.

Getting the label wording exactly as the grant specifies matters, a label that omits a required line is a real, citable non-conformity.

Modular approval

Radio modules are certified once and reused across many host products, which is what makes them attractive. The FCC defines two flavors of modular grant, and the difference decides how much an integrator inherits.

Single Modular Approval

A module qualifies for Single (full) Modular Approval when it meets all of the FCC's modular requirements on its own, broadly:

its own RF shielding;
buffered modulation and data inputs;
its own power supply regulation;
compliance with antenna requirements (a permanently attached or uniquely-connectored antenna);
it is tested in a stand-alone configuration;
it carries its own FCC ID label;
it complies with the applicable RF exposure rules;
it meets the relevant Part 15 (or other) operating requirements.

A fully approved module can be integrated into essentially any host with only the standard integration obligations. The integrator inherits the radio certification.

Limited Modular Approval

When one or more of those eight conditions is satisfied by the host rather than by the module (for example, the shielding is provided by the host enclosure, or the antenna is host-specific), the TCB grants Limited Modular Approval (LMA). The grant then carries explicit conditions the integrator must honor.

Aspect	Single Modular Approval	Limited Modular Approval
Modular conditions met by	The module alone	Module plus host (some conditions on the host)
Integration freedom	Broad, any compliant host	Restricted to the conditions in the grant
What the integrator inherits	The full radio certification	The certification subject to host conditions
Risk if conditions ignored	Low	The grant may not cover the integration

What an integrator actually inherits

Inheriting a module's grant is powerful but bounded. The integrator must:

respect every grant condition and every instruction in the module's integration manual;
keep the antenna within the certified types and gains;
carry the "Contains FCC ID" labeling;
re-assess RF exposure (SAR or MPE) for the actual host geometry, because exposure depends on how close the antenna sits to the user, which the module grant cannot know in advance;
treat any change beyond the grant conditions as triggering its own filing.

An integrator who buys a fully-certified module, follows the integration manual exactly and does not alter the RF chain typically does not need a new certification for the radio itself. Deviate from the conditions and that inheritance evaporates.

Permissive changes

Once a product is certified, changes are governed by the FCC's permissive change framework, which classifies modifications and tells you when an existing FCC ID can be kept versus when a new authorization is required.

Class	Nature of change	Effect on the FCC ID
Class I	No degradation of compliance; no filing required	FCC ID unchanged, no TCB action
Class II	Changes that affect compliance but stay within the same basic design	Same FCC ID, but a Class II permissive change filing through the TCB
Class III	Software or RF parameter changes in software-defined or modular contexts	Filed under the specific rules for that change type

The boundaries between these classes, and the documentation each one demands, are detailed in the dedicated Class II permissive change guide. The practical rule of thumb: a change that could affect emissions, frequency, power or the RF front end is almost never Class I. When in doubt, ask the TCB before shipping the modified product.

Relationship with ISED Canada

The United States and Canada run separate but closely aligned regimes. ISED Canada (formerly Industry Canada) certifies radio apparatus under its own rules and issues its own identifier, the IC number, structured analogously to the FCC ID (a company prefix plus a product suffix).

Aspect	FCC (United States)	ISED (Canada)
Identifier	FCC ID	IC number
Procedure for radios	Certification via TCB	Certification via recognized Certification Body
Self-declaration path	SDoC	Self-declaration for certain categories
Test data	Largely shared	Largely shared (same lab campaign)

Because the technical requirements overlap so heavily, a single test campaign usually serves both jurisdictions, and many TCBs are also ISED-recognized Certification Bodies, so one provider can handle both grants. They remain, however, two separate filings producing two separate identifiers. The ISED Canada radio certification guide covers the Canadian side, including the MRA arrangements that let recognized bodies grant across borders.

A practical sequence

For a typical connected product with an integrated radio, the path looks like this:

Classify the device: it contains an intentional radiator, so it needs Certification.
Register an FRN in CORES, then apply for a Grantee Code (once per company).
Test at an accredited ISO/IEC 17025 lab against the applicable Part 15 (and other) rules, after reading the relevant KDB guidance.
Choose an Equipment Product Code and assemble the FCC ID.
File with a TCB, which reviews and issues the grant of authorization.
Label the product with the full FCC ID (or e-label), and prepare the user manual exhibits.
Verify the published grant in the FCC ID search once it appears in the database.
Plan for change management: classify any future modification under the permissive-change framework, and file the parallel ISED grant if Canada is in scope.

For a device with only an unintentional radiator, steps 2, 4, 5 and 7 fall away: you test, document, sign the SDoC compliance statement, and apply the SDoC label.