If you're selling to the US and your product has radio transmission capability – FCC is unavoidable. FCC is the US Federal Communications Commission – they regulate more than you think: Wi‑Fi, Bluetooth, cellular, NFC all fall under them – even the electromagnetic interference from pure electronic products.

US law is very clear: any RF device sold, imported, or used in the US must have FCC authorisation. No certificate – no listing. If caught – fines, mandatory recalls, customs holds. Amazon and Best Buy have tightened their review processes over the past two years – they now require FCC documentation before listing – without it, they simply reject.

一、Three Paths – Most People Only Tell Half the Story

FCC equipment authorisation actually has three paths: Certification, SDoC, and Verification. Verification is rarely used today – but before the 2017 reform, it and DoC were two separate paths – older materials that list them separately are not outdated.

SDoC replaced the old VoC. In November 2018, FCC merged Verification and DoC into the current SDoC. Most online guides only mention two paths – missing this history. When a client asks if an old VoC report is still usable – knowing this history helps you respond correctly.

One trap beginners miss: a whole product with a wireless module that already has an FCC ID – the whole product still needs Part 15B testing. You install an FCC‑ID‑certified Wi‑Fi module – the whole product's radiated and conducted EMC emissions must still meet Part 15B limits. FCC RF authorisation and Part 15B EMC are two separate systems – neither substitutes for the other.

1. SDoC – which products?

SDoC (Supplier's Declaration of Conformity) – manufacturers test themselves, sign themselves, and take responsibility themselves. Like a letter of guarantee – no one reviews it, but if something goes wrong, you're on the hook. Applicable scope is narrow: unintentional radiators – devices that don't actively transmit but generate electromagnetic interference when operating. Pure wired electronics, displays without wireless modules, industrial controllers – this path is sufficient.

2. Certification – which products?

Certification – formal FCC certification – for intentional radiators. Wi‑Fi, Bluetooth, Zigbee, LoRa, cellular, NFC, RFID – anything that actively emits RF signals – must go through the full process. Self‑declaration is not allowed. Labs must have ISO 17025 accreditation – data goes to a TCB – TCB approves and issues an FCC ID.

In our projects, head‑unit clients are most prone to confusion: "the 4G module already has an FCC ID – so the whole product is done" – forgetting that Wi‑Fi and Bluetooth also need testing.

How to determine:

·Does the product have an active RF transmission module? Yes → Certification.

·No → SDoC.

Don't overthink it.

  二、How FCC ID Works

Each Certification product gets a unique FCC ID – format: Grantee Code + Product Code.

·Grantee Code: permanent company number – FCC official fee USD 35. The USD 60 you sometimes hear is a bundled price – including platform and admin fees – make sure the quote shows this clearly – otherwise your client will question it.

·Product Code: company‑assigned – max 14 characters – used to distinguish different models.

The FCC ID is printed directly on the product label – publicly searchable in the FCC database – anyone can look up the corresponding test reports and RF parameters.

FCC ID has no fixed expiry date. As long as the product hardware and RF design remain unchanged – the certificate stays valid. It only becomes invalid in three cases:

·Major product modification without change filing.

·Regulatory standard updates forcing mandatory retesting.

·Company proactively cancels.

There is no annual audit. There is no renewal fee. I've had clients who were told by agents "FCC ID needs annual inspection" – and paid for years before realising it was unnecessary.

  三、What RF Tests Cover

2.4 GHz Wi‑Fi and Bluetooth – Part 15C (§15.247) – tests output power, out‑of‑band spurious, occupied bandwidth, frequency stability. Conducted transmit power limit: 1W. If antenna gain exceeds 6 dBi – you must reduce conducted power to keep EIRP compliant. It's not a blanket 1W limit – stronger antennas require reducing transmit power. There's no universal formula for power calculation – run it through a lab – that's more reliable than guessing.

1. 5 GHz and 6 GHz

5 GHz Wi‑Fi – Part 15E – divided into UNII‑1/2/3 sub‑bands – each with different power limits. UNII‑2 requires DFS – radar detection and channel avoidance – the most common failure in 5 GHz certification. I've seen clients go through multiple DFS test rounds before passing.

6 GHz Wi‑Fi – also Part 15E.

2. AFC – who actually needs it?

AFC is not only for APs. Standard‑power fixed clients also need AFC. Only LPI low‑power indoor clients and mobile clients are exempt. Don't just say "STA doesn't need AFC" – that myth has misled many, and I've made that mistake in early proposals myself.

Cellular modules – in addition to Part 22/24/27 – 5G NR also involves Part 90. In‑vehicle cellular terminals also require distinguishing mobile vs. portable SAR assessment – one template doesn't fit all. NFC and RFID – Part 15C §15.225 – 13.56 MHz.

  四、FCC Module Integration – The Biggest Trap

This is the most misunderstood point in FCC certification – nothing else comes close.

A Full Modular Approval module – meeting all KDB 996369 conditions – when integrated into a whole product, the whole product does not need a separate FCC ID. SDoC Part 15B is sufficient – ship directly. Note: I said "can" – provided all conditions are met.

Don't get excited yet – listen to the conditions. Limited Module integration into a whole product – you generally cannot avoid whole‑product certification. When you get the module, check first – Full or Limited? Assuming "it's fine" – you're setting yourself up for failure.

If Full Modular conditions are met – you don't change the RF circuit, add a PA, change the antenna outside the approved range, or introduce additional interference – the whole product can reference the module data via SDoC. Change the antenna type – e.g., the module was originally certified with a PCB antenna – you swap to an external whip – impedance and gain characteristics change – all previous data is invalid – full RF retesting required.

  五、Changes – Retest or Not?

Class I changes: modifications that do not affect RF performance – appearance colour, non‑metallic housing, silkscreen position, packaging. Remember: Class I does not require any TCB filing – the company keeps its own assessment records. The industry assumption "filing is required" is a widespread misconception – even some agency internal training teaches this.

Class II changes: RF hardware changes – antenna replacement, power adjustment, RF chip change, crystal change – definitely retest.

Software changes – distinguish:

·Upper‑layer UI/application changes with no RF‑layer parameter changes – Class I.

·Changes to transmit power control, frequency‑hopping logic, or DFS detection strategy – Class II.

Note: SDR devices have their own change rules – not covered by this framework.

  六、Multi‑Radio Products – How to Handle

One head unit with Wi‑Fi, Bluetooth, 4G cellular, and NFC – one FCC ID covers everything – no problem. Each radio type is fully tested – one report with all Part data – TCB reviews item by item. Any band fails – the entire FCC ID is held up.

I've had clients trip on this: later removing or adding a radio type is a major change – you cannot simply reuse the original FCC ID. Directly coordinate with the TCB on the change assessment path – don't act first and notify later.

For FCC certification, contact BlueAsia at 13534225140 (King) or email king.guo@cblueasia.com.