Wireless
Wireless Microphone Legal Requirements in the USA
Quick answer
In the US the legal working band for church wireless microphones is 470 to 608 MHz, at up to 50 milliwatts without a licence. TV channel 37 at 608 to 614 MHz is prohibited, 614 to 616 MHz is a 20 milliwatt duplex gap, and 617 to 652, 663 to 698 and 698 to 806 MHz are illegal to operate.
This is the page where being wrong has legal consequences rather than musical ones, so it is written plainly. After the 600 MHz repack, large blocks of spectrum that churches bought equipment for are now licensed to mobile carriers, and operating a microphone in them is prohibited. That equipment still appears in listings every week, sold by people who do not know or do not say.
Check the tuning range printed on the back of any receiver before you buy it, plug it in or accept it as a donation. If the range falls inside 617 to 652 MHz or 663 to 698 MHz it cannot be legally operated in the United States, it cannot be retuned by a dealer, and it has no value beyond scrap. The band-by-band detail is at the wireless frequency reference, and the practical channel planning is in how to coordinate wireless microphone frequencies.
On this page
The complete US band picture for a church
Read this table before any wireless purchase, new or used. The legal column is the only one that matters first, and the licence column tells you what rules apply once you are in a legal band.
The working band for a US church is 470 to 608 MHz, and 617 to 698 MHz is entirely off limits.
| Band | Legal for microphones? | Rule and power | What a church should know |
|---|---|---|---|
| VHF 169 to 216 MHz | Legal | Unlicensed, Part 15 | Crowded, antenna-hungry, and the home of the cheapest systems. Range suffers indoors. |
| UHF 470 to 608 MHz (TV 14 to 36) | Legal | Part 15 at 50 mW, or Part 74 licence at 250 mW | The main working band. You must sit in TV channels that are vacant at your address. |
| 608 to 614 MHz (TV channel 37) | Prohibited | Never permitted | Radio astronomy and wireless medical telemetry. Never legal for microphones. |
| 614 to 616 MHz guard band | Legal | Part 15, 20 mW limit | A 2 MHz sliver good for two or three channels at reduced range. |
| 617 to 652 MHz | Illegal | Prohibited since the repack | Sold to mobile carriers. Gear tuned here is worthless. |
| 663 to 698 MHz | Illegal | Prohibited since the repack | Sold to mobile carriers. Gear tuned here is worthless. |
| 698 to 806 MHz | Illegal | Prohibited since 2010 | Public safety and mobile broadband. Any pre-2010 system may sit here. |
| 902 to 928 MHz ISM | Legal | Unlicensed, Part 15 | Shares space with cordless phones and telemetry. Fine for a handful of channels. |
| 1920 to 1930 MHz DECT | Legal | Unlicensed | Self-coordinating, very easy to deploy, limited range and channel count. |
| 2.4 GHz ISM | Legal | Unlicensed, Part 15 | Shares the band with every Wi-Fi access point in the building. |
| 5.8 GHz ISM | Legal | Unlicensed, Part 15 | Cleaner than 2.4 GHz in most buildings, shorter range, needs line of sight. |
This is the US position only. Other countries allocate wireless microphone spectrum differently, so a system bought abroad or online from an overseas seller may be illegal here even if it is legal where it shipped from.
How to check a system before you buy it
- Read the frequency range off the receiver. Every legitimate receiver has its tuning range printed on the rear panel or on a label, usually as a band letter and a megahertz range such as H10 or 542 to 572 MHz. If the seller cannot photograph that label, assume the worst.
- Map the band letter to actual megahertz. Band letters differ between manufacturers and between generations of the same manufacturer, so look the specific letter up in that manufacturer documentation rather than trusting a general chart. Confirm the whole range, because a system that starts at 596 MHz and ends at 620 MHz crosses into prohibited spectrum.
- Reject anything touching 617 to 698 MHz. If any part of the tuning range falls in 617 to 652 or 663 to 698 MHz, do not buy it. Retuning is not possible on these systems. A range that merely includes the 608 to 616 MHz area may still be usable if the system can be locked out of channel 37, but a receiver whose whole range sits above 617 MHz is scrap.
- Check the TV channels vacant at your address. A legal band is not the same as a usable band. Use the FCC tools or manufacturer coordination software with your street address to confirm there are vacant TV channels inside the tuning range of the system you are considering.
- Confirm the power rating and the antenna. Unlicensed operation in the TV band is limited to 50 milliwatts, and 20 milliwatts in the duplex gap. Do not fit aftermarket amplified antennas or transmit boosters, which are not legal for these devices and which turn a compliant system into a non-compliant one.
- Document the purchase. Keep the model, band, tuning range and serial numbers in the church records alongside the coordinated frequency list. When the next repack conversation happens, that list is what tells you in ten minutes whether your inventory is affected.
Do churches need a Part 74 licence?
Almost never, and the reason is eligibility rather than paperwork. Part 74 subpart H licences for low power auxiliary stations were written for broadcasters and film production, and eligibility was later extended to operators who routinely use large numbers of wireless microphones, on the order of 50 or more. A church running six or ten channels does not qualify.
What a church does instead is operate unlicensed under Part 15, which permits wireless microphone use in vacant TV channels at up to 50 milliwatts. That is a legal, normal and completely sufficient way to run a church system, and the only obligations are to stay in vacant channels, to stay within the power limit and to accept that you have no protection from interference. The licence question is explored further in wireless microphone licensing under Part 74.
Unlicensed also means unprotected. If a TV station signs on in a channel you were using, you move. That is the deal, and it is another reason to write your frequency plan down and to own systems with a wide tuning range rather than fixed-frequency ones.
What the repack actually did to churches
The 600 MHz band was auctioned to mobile carriers and television stations were repacked into a narrower slice of UHF. Two things followed for churches. The obvious one is that equipment operating in 617 to 698 MHz had to stop, and a transition period ended years ago. The subtler one is that the working band shrank from roughly 470 to 698 MHz down to 470 to 608 MHz, so there are fewer vacant TV channels in every market and coordination is harder than it was.
The practical consequence today is that channel capacity is tighter, digital systems have a bigger advantage than they used to, and any second-hand bargain deserves suspicion. The background is in how the 600 MHz repack affected churches, and the buying rules are in buying used church sound equipment.
If your church still owns affected gear, it is not a trade-in and it is not a donation to a smaller church either. Passing prohibited equipment along simply moves the problem onto a congregation with less expertise to spot it.
Buying legal, today
New systems sold by US dealers are tuned to legal bands, so the simplest protection is to buy new from a reputable seller. In the entry tier Shure BLX24/SM58 Wireless Microphone System - 14-Hour Battery Life, 300 ft Range, UHF and Sennheiser Pro Audio XSW 1-825-A Vocal Wireless Microphone, A Range 548-572 MHz, Black, medium are legal current systems. In the digital tier Shure SLXD24/SM58 Digital Wireless Microphone System - Includes SLXD2 Handheld Transmitter with SM58 Vocal Mic Capsule and SLXD4 Single Channel Rack Mount Receiver and Sennheiser Pro Audio EW-D 835-S Wireless Handheld Microphone System, R1-R6 tune across wide legal ranges, which matters because a wide range survives future changes better than a narrow one.
If you want to sidestep TV spectrum altogether, Shure GLXD24+/SM58 Digital Wireless Vocal System - Z3 Band operates in the 2.4 GHz ISM band, which is unlicensed and legal nationwide, at the cost of sharing the band with your Wi-Fi. For a church plant or a portable rig that is often the right trade. Options across the price range are compared in best wireless microphones for churches and, for smaller rooms, wireless microphones for small churches.
Sources
Frequently asked questions
Is it actually illegal for a church to use a 600 MHz wireless microphone?
Yes. Operating a wireless microphone in 617 to 652 MHz or 663 to 698 MHz is prohibited in the United States regardless of who is operating it or how quietly. That spectrum is licensed to mobile carriers, and interference there affects services that emergency calls depend on. There is no church exemption, no low-power exemption and no grandfathering.
Can a dealer retune an old system into a legal band?
No. The radio hardware, filters and antennas in a wireless system are designed for a specific frequency range, and moving a system from 650 MHz into the 500 MHz range is not a firmware change. Some manufacturers ran trade-in programmes during the transition, but those have closed. Equipment tuned to prohibited spectrum has no legal use in the US.
What power level may a church transmit at?
Up to 50 milliwatts in vacant TV channels between 470 and 608 MHz when operating unlicensed under Part 15, and up to 20 milliwatts in the 614 to 616 MHz guard band. A Part 74 licence permits 250 milliwatts, but eligibility generally requires routinely using 50 or more wireless microphones, which excludes almost every congregation.
How do I know which TV channels are vacant at our building?
Use the FCC TV query tools or your manufacturer coordination software with your exact street address rather than your city. Vacant channels vary across a metropolitan area, and two churches ten miles apart can have different lists. Re-check after any change in local broadcast licences, because unlicensed operation carries no protection and you are required to move.
Are 2.4 GHz systems legal everywhere in the US?
Yes. The 2.4 GHz ISM band is unlicensed and legal nationwide, as are 902 to 928 MHz, 1920 to 1930 MHz DECT and 5.8 GHz. The trade-off is sharing: 2.4 GHz carries every Wi-Fi network in the building, so channel counts are lower and range is shorter. For two to four channels in a small or portable setting it is an excellent answer.
What happens if someone reports interference from our system?
Unlicensed operation under Part 15 comes with two conditions: you may not cause harmful interference, and you must accept interference from licensed services. If your system interferes with a licensed user you are required to stop operating until it is resolved. Operating in prohibited spectrum is a separate and more serious matter that can carry enforcement penalties.
Researched, not professional advice. This page is compiled from published manufacturer specifications, operator manuals, FCC rules, published standards and owner-review consensus, not hands-on testing. Sound system design, rigging loudspeakers overhead, and any electrical work are jobs for a qualified professional: have flown loudspeakers and their attachment points signed off by a structural engineer or a certified rigger, and have all wiring done by a licensed electrician to your local code. Wireless microphone rules change, so confirm the current FCC position before buying. As an Amazon Associate we earn from qualifying purchases.