Do you need an FCC license for wireless microphones?
No — wireless microphones can be operated legally in the United States without any licence, under the Part 15 rules in §15.236, at 50 mW EIRP in the TV bands. A Part 74 low power auxiliary station licence is optional and only available to specific classes of applicant listed in §74.832(a): broadcasters, broadcast networks, cable operators producing programming, motion picture and television producers, Broadband Radio Service licensees, and — since the FCC's 2014 Second Report and Order — large venue owners or operators and professional sound companies that routinely use 50 or more devices. The licence buys higher power in 470–608 MHz, access to bands unlicensed users cannot touch, and standing to register in the white space database.
The short answer is no: you do not need a licence to run wireless microphones in the United States, and the overwhelming majority of working mixers never have one. The longer answer is that a Part 74 low power auxiliary station licence exists, it is worth real money in specific situations, and since 2014 far more sound professionals have been eligible for one than realise it.
What a Part 74 licence actually buys you
| Unlicensed (Part 15) | Licensed (Part 74) | |
|---|---|---|
| 470–608 MHz power | 50 mW EIRP | 250 mW conducted |
| 600 MHz duplex gap | 657–663 MHz only, 20 mW | 653–657 MHz, 20 mW |
| 941.5–959.85 MHz | No | Yes, if eligible for that band |
| 1435–1525 MHz | No | Yes, if eligible for that band |
| 6875–6900 and 7100–7125 MHz | No | Yes, if eligible for that band |
| White space database registration | No | Yes |
The power difference is the headline. Note that the two figures are not measured the same way — 250 mW is conducted power at the antenna terminal, 50 mW is EIRP, so the nominal five-fold gap is not a like-for-like comparison (see ERP and EIRP in the glossary). In practice it is still the difference between a transmitter that survives a walk behind a concrete stairwell and one that does not. The database registration is narrower than it sounds — see registering in the white space database — but it is the only mechanism that gets any wireless microphone affirmative protection from anything.
Who is eligible
Eligibility is set out in §74.832(a). It is a closed list. If you are not on it, no amount of professionalism or gear count makes you eligible.
- Licensees of AM, FM, TV or International broadcast stations, and low power TV stations
- Broadcast network entities
- Cable television system operators, where the equipment is used to produce program material
- Motion picture producers
- Television program producers
- Broadband Radio Service licensees
- Large venue owners or operators — added 2014
- Professional sound companies — added 2014
Those last two are the ones that changed the picture for production audio. They came in with the FCC's 2014 Second Report and Order (29 FCC Rcd 6103, published at 79 FR 40680 on July 14, 2014) and were reaffirmed in FCC 15-100, adopted August 5, 2015. Before that, a sound company with two hundred channels of wireless and no broadcast affiliation had no path to a licence at all.
How to apply
- Register in the FCC's Universal Licensing System (ULS) and obtain an FRN if you do not already have one.
- File FCC Form 601 through ULS, selecting the low power auxiliary station service.
- State the maximum number of units you are seeking authority for. One application covers multiple devices — you are not filing per transmitter.
- If you are applying as a large venue owner/operator or professional sound company, include the 50-device certification and attach the explanatory sheet.
- Licence term
- For the large-venue and professional-sound-company category,
47 CFR §74.15(b)sets a term not to exceed ten years from the date of initial issuance or renewal. - Broadcast-affiliated licences
- Auxiliary licences held by or through a broadcast station run concurrently with the associated broadcast station licence rather than on their own ten-year clock.
- Station identification
- Licensed operation carries station identification obligations under
§74.882. Read it once when the licence lands rather than the first time somebody asks.
If you are not eligible
Unlicensed operation under §15.236 is a legitimate, fully legal way to work, and it is what nearly all owner-operators are doing. The trade is power and protection.
| Band | Power |
|---|---|
| 54–72, 76–88, 174–216, 470–608 MHz | 50 mW EIRP |
| 614–616 MHz | 20 mW EIRP |
| 657–663 MHz | 20 mW EIRP |
- Frequency tolerance: ±0.005%
- Maximum bandwidth for narrowband operation: 200 kHz
- You must accept any interference you receive, and you may not cause harmful interference to a licensed service
That last point is the whole of unlicensed status in one line. If a repacked television station lands on your frequency, the station is right and you are wrong, and the remedy is that you move. Which is an argument for knowing what is on the air near the location before the truck rolls, licence or no licence.
Is it worth getting one?
If you are a one-bag owner-operator running four to eight channels, probably not. The extra power is nice and the extra bands are unreachable without new hardware, and nothing about a licence makes a crowded market less crowded. If you run a rental house, a venue, a large-format live event, or a broadcast-adjacent operation with dozens of channels going out on a regular basis, it is straightforwardly worth the filing — the power headroom alone changes what you can do in difficult buildings.
What a licence does not do is exempt you from coordination. Licensed operators are still secondary to broadcasters, still have to plan around each other, and still get taken apart by intermodulation if the frequency plan is careless.
Licensed or not, the constraint that bites is what is already transmitting near your location. Get an advisory before you commit to a plan.
Plan the frequencies firstCommon questions
- Do I need an FCC license to use wireless microphones?
- No. Wireless microphones may be operated without a licence under Part 15 rules in 54–72, 76–88, 174–216 and 470–608 MHz at 50 mW EIRP, plus 614–616 and 657–663 MHz at 20 mW. A Part 74 licence is optional and restricted to the classes of applicant listed in §74.832(a).
- Can a production sound mixer get a Part 74 license?
- It depends on how you are organised. Motion picture producers and television program producers have always been eligible, and the FCC's 2014 Second Report and Order added large venue owners or operators and professional sound companies. Those two newer categories must certify that they routinely use 50 or more low power auxiliary station devices as an integral part of major events or productions.
- How do you apply for a wireless microphone license?
- File FCC Form 601 through the Universal Licensing System, selecting the low power auxiliary station service. A single application can cover multiple units — the applicant states the maximum number of units — and venue or professional sound company applicants attach a sheet explaining how they meet the 50-device standard.
- How long does a Part 74 wireless microphone license last?
- For the large-venue and professional-sound-company category, 47 CFR §74.15(b) sets a term not to exceed ten years from initial issuance or renewal. Auxiliary licences tied to a broadcast station instead run concurrently with that station's licence.
- What happens if you operate wireless microphones illegally?
- Unlicensed operators must accept interference and must not cause harmful interference to licensed services, and operating in prohibited spectrum such as 617–698 MHz or channel 37 is a rule violation. Documented FCC enforcement in this area has centred on manufacturers and marketers of non-compliant gear rather than individual operators — the most common practical consequence for a mixer is being told to shut down.
Sources
Related notes
Field Notes are general reference, not legal advice or a substitute for the rule text. Spectrum rules change; verify anything you are relying on against the current source before you transmit. See the methodology and disclaimer.