FRS/GMRS Privacy Codes Demystified

I have a love/hate relationship with FRS/GMRS radios. They are inexpensive, and you can buy them practically anywhere. They are great for the kids to play with, and are very useful when camping, boating, hiking, or driving in a convoy with your friends. However, the range is short and the antennas are not (usually) replaceable. Nevertheless they work pretty well as long as everyone has the same brand of radio. But if you are trying to talk to people who have different a different brand of radio than yours, things can get a bit trickier.

This page will probably help you out if:

The easiest way to make different manufacturer radios talk to each other is to put them on the same channel and turn off the privacy codes (or sub codes, or interference eliminator codes, or whatever your radio calls them). If you want to use a privacy code, keep in mind that they don't give you any privacy. You can usually pick one that's less than 38 and it will work. My guess is that you already tried it and it didn't work, so you went a searching and found this page.

Channels and Frequencies

Almost all FRS and GMRS radios use channel numbers as a substitute for the frequency (the Baofeng GMRS-50X1 lets you set the frequency directly). The frequencies and channels are defined by the FCC. Note that while FRS and GMRS share the same frequencies and channels, FRS radios are limited to lower power output. If you are only communicating over short distances and there are many nearby FRS/GMRS radios, you may be better served to use channels 8-14. On the other hand, if you want to maximize the distance of your communications, you should choose channels 1-7 or 15-22.

ChannelFrequencyFRS PowerGMRS Power
01462.56252 W5 W
02462.58752 W5 W
03462.61252 W5 W
04462.63752 W5 W
05462.66252 W5 W
06462.68752 W5 W
07462.71252 W5 W
08467.56250.5 W0.5 W
09467.58750.5 W0.5 W
10467.61250.5 W0.5 W
11467.63750.5 W0.5 W
12467.66250.5 W0.5 W
13467.68750.5 W0.5 W
14467.71250.5 W0.5 W
15462.55002 W50 W
16462.57502 W50 W
17462.60002 W50 W
18462.62502 W50 W
19462.65002 W50 W
20462.67502 W50 W
21462.70002 W50 W
22462.72502 W50 W
 467.5500 50 W
 467.5750 50 W
 467.6000 50 W
 467.6250 50 W
 467.6500 50 W
 467.6750 50 W
 467.7000 50 W
 467.7250 50 W

Many handheld FRS/GMRS radios do not transmit at the maximum power limit. For example, a Motorola T600 has a maximum transmit power of 1.5 W. My Cobra HH450 can transmit on GMRS at 1 W, 2 W, or 3 W.

In September 2017 the FCC combined and standardized the FRS and GMRS frequencies, which codified the common practice used by most manufacturers. Most radios built before September 2017 use the modern channel frequencies in the chart above. Some older GMRS only radios, like the Midland MXT105, don't transmit on channels 8-14 because those channels were previously designated as FRS only. The good news is that most of those radios just omit those channels from their settings. Channel 20 on the MXT105 works with everybody else's channel 20.

The last 8 frequencies in the chart, the ones without channel designations, are for use as repeater input frequencies. Most GMRS radios are designed for simplex operation and can't transmit on these frequencies. Which mostly doesn't matter because there are very few GMRS repeaters out there.

What is Squelch Anyway?

GMRS/FRS channels mostly just work no matter who manufactured the radio. However, it's not so smooth when it comes to the so called privacy codes. Motorola calls them interference eliminator codes. Uniden sometimes calls them sub codes. All these words are synonyms for either analog or digital squelch, and sometimes a synonym for both, which is unfortunate. If you are a ham radio operator, you probably know what squelch means. If the word squelch makes you think of that time you almost threw up and it went all the way to the back of your throat, don't worry, it's not that. Here's a metaphor to explain.

Say you have 10 friends all in the same room at the same time. You assign two of your friends code 1, two friends code 2, two friends code 3, and so forth. Everyone starts whispering except one person, who starts talking. It's easier for you to listen to the person talking, because they are louder than everyone else. That's squelch. Now, everyone starts talking at the same time. If you are assigned to code 4, you try really hard to only listen to the other person who is assigned to code 4. That's tone squelch. But if you really want to listen to the conversation going on between the two people assigned to code 5, you could do that too. In other words, squelch just tells your radio what to listen for, it has nothing to do with what is transmitted.

You can test this out for yourself if you have two FRS/GMRS radios. Set them both to the same channel, and then set one of them to use privacy code 5. Turn off the privacy code, or set it to 0, on the other radio. When you transmit on the radio with privacy code 5, you will still be able to hear the transmission on the radio with the privacy codes off. But when you transmit on the radio with the privacy codes off, the radio set to privacy code 5 won't be able to hear. It's not that the transmission wasn't sent, it's just that the radio is ignoring all transmissions without privacy code 5.

In real life, there are three basic types of squelch. The first is based on signal strength. The signal received by your radio has to be of a certain strength in order for your radio to decide it's important enough for you to hear it. Turn the squelch down and you will hear all kinds of fuzzy signals. Turn the squelch up and you will hear only the stronger signals. Most FRS and GMRS radios don't have this type of squelch setting.

The second type of squelch works by adding a low frequency tone to the transmission. The receiving radio ignores all signals that do not contain the specified tone. The tone is stripped out by the receiving radio before sending the signal to a speaker or headset. The real name for this method of transmission is Continuous Tone-Coded Squelch System or CTCSS. Most modern FRS and GMRS radios have CTCSS, but most of them don't call it CTCSS.

Digital Coded Squelch or DCS is the third type, and it works by adding a sub-audible digital bitstream to the transmitted audio. The bitstream is used to transmit a code along with the audio. The radio ignores signals that do not include a bitstream with the specified code. Many FRS and GMRS radios, especially the higher end models, have DCS, but like CTCSS, most of these radios don't call it DCS.

Privacy Codes

In an effort to avoid a long discussion like we just had about CTCSS and DCS, the FRS and GMRS radio manufacturers came up with different words to describe tone or digital squelch. Motorola uses "Private Line" or "PL" codes. They also use "interference eliminator codes". Radio Shack (remember them?) used to call them "quiet codes". Many manufacturers call them "privacy codes". These consumer friendly terms refer to both CTCSS and DCS. Which makes everything confusing when trying to figure out how to make radios from different brands talk to each other. To make the description easier from here on out, we'll just call them privacy codes. Just remember, they have nothing to do with privacy.

You don't have to use privacy codes. The easiest way to make your different brand radios talk to each other is to turn the privacy codes off. On many radios you turn the privacy code off by setting it to 0.

Some radios don't have privacy codes, like the Midland LXT118. That means you hear everyone on your channel, whether they use a privacy code or not. But it also means that nobody using a privacy code can hear you. They have to turn their codes off in order to listen to your transmission.

I love my Cobra HH450. It doesn't have the FRS-only frequencies because it has a detachable antenna; the FCC doesn't allow detachable antennas on FRS radios. It has the pre-2017 GMRS channels and it transmits and receives on the marine VHF channels. It's submersible and receives NOAA weather broadcasts. It's a great radio to take to the lake. Even better, it doesn't have "privacy codes". It has a way to turn on CTCSS and set the tone, or you can turn on DCS and set the code. This approach is works great for a ham operator like me, but may be overwhelming for unlicensed operators. But how do I know which privacy code to use on my Motorola MT351R when I set a CTCSS frequency of 88.5 Hz on the Cobra?

CTCSS-based Privacy Codes

CTCSS works by adding a low frequency tone to the transmitted signal. Radios configured to use CTCSS filter out any signals that don't contain the designated low frequency tone. There are more than 50 tone frequencies that work for CTCSS, but only 38 of them are commonly used on FRS or GMRS radios. A few radios (like the Cobra HH450, Jetstream JT270M, Baofeng GMRS-50X1 and Baofeng GMRS-V1) allow you to set the tone frequency directly. For most radios the manufacturer represents the various tone frequencies with a "privacy code". Lucky for us, they mostly chose the same assignments. The following chart shows a map between the CTCSS frequencies and privacy codes. The "Common" column is used by most manufacturers, including:

Freq (Hz)CommonCherokee 465Motorola SportRadio Shack
67.011 1
69.3 2  
69.4   2
71.923 3
74.434 4
77.045A5
79.756 6
82.567 7
85.478 8
88.589B9
91.5910 10
94.81011 11
97.41112C12
100.01213 13
103.51314 14
107.21415D15
110.91516 16
114.81617 17
118.81718E18
123.01819 19
127.31920F20
131.82021 21
136.52122G22
141.32223 23
146.22324 24
151.42425 25
156.72526 26
159.8 27 27
162.22628 28
165.5   29
167.92729 30
171.3   31
173.82830 32
177.3   33
177.8    
179.92931 34
183.5 32 35
186.23033 36
189.9 34 37
192.83135 38
196.6 36  
199.5 37  
203.53238  
206.5 39  
210.73340  
218.13441  
225.73542  
229.1 43  
233.63644  
241.83745  
250.33846  
254.1 47 

DCS-based Privacy Codes

Digital Coded Squelch works by transmitting a digital bitstream with the audio. The bitstream is encoded with error correction and can accommodate 512 different squelch codes. These codes are typically represented as an octal (base 8) number. However, because of the way the codes are packed into the bitstream, there is a possibility of misalignment errors upon decoding. To reduce the potential for decoding errors, most manufacturers only use 83 of the 512 codes. However, some Midland radios and the Baofeng radios can use any DCS code. In fact, the Baofeng and Jetstream radios can use inverted DCS codes (too complicated to explain here). Not sure why you would ever want or need that, so I've omitted them from the chart.

Many radios just have one set of numbered privacy codes, and you have to magically know where it switches from CTCSS to DCS. This is how my Motorola MT351R works. Privacy code 38 is CTCSS with a 250.3 Hz tone, privacy code 39 is DCS using code 023. The MT351R has 121 privacy codes, 38 CTCSS tones, and 83 DCS codes.

The DCS-based privacy codes have been implemented two different ways. Uniden, Motorola, and Backcountry Access just keep the privacy code numbers going, and switch from CTCSS to DCS at code 39. Midland and Cobra have a separate DCS mode, and the privacy codes start over at 1.

In this chart the "Common" column is used by the following manufacturers radios:

DCS CodeBaofeng GMRS-V1CommonCobraMidland
023D023N3911
025D025N4022
026D026N4133
031D031N4244
032D032N4355
036D026N  84
043D043N4466
047D047N4577
051D051N4688
053D053N  85
054D054N4799
065D065N481010
071D071N491111
072D072N501212
073D073N511313
074D074N521414
114D114N531515
115D115N541616
116D116N551717
122D122N  86
125D125N561818
131D131N571919
132D132N582020
134D134N592121
143D143N602222
145D145N  87
152D152N612323
155D155N622424
156D156N632525
162D162N642626
165D165N652727
172D172N662828
174D174N672929
205D205N683030
212D212N  88
223D223N693131
225D225N  89
226D226N703232
243D243N713333
244D244N723434
245D245N733535
246D246N  90
251D251N743636
252D252N  91
255D255N  92
261D261N753737
263D263N763838
265D265N773939
266D266N  93
271D271N784040
274D274N  94
306D306N794141
311D311N804242
315D315N814343
325D325N  95
331D331N824444
332D332N  96
343D343N834545
346D346N844646
351D351N854747
356D356N  97
364D364N864848
365D365N874949
371D371N885050
411D411N895151
412D412N905252
413D412N915353
423D423N925454
431D431N935555
432D432N945656
445D445N955757
446D446N  98
452D452N  99
454D454N  100
455D455N  101
462D462N  102
464D464N965858
465D465N975959
466D466N986060
503D503N996161
506D506N1006262
516D516N1016363
523D523N  103
526D526N  104
532D532N1026464
546D546N1036565
565D565N1046666
606D606N1056767
612D612N1066868
624D624N1076969
627D627N1087070
631D631N1097171
632D632N1107272
645D645N   
654D654N1117373
662D662N1127474
664D664N1137575
703D703N1147676
712D712N1157777
718    
723D723N1167878
731D731N1177979
732D732N1188080
734D734N1198181
743D743N1208282
754D754N1218383

Some Midland radios, like the T70 series, only have 83 DCS privacy codes. Others, like the MXT105, have 104. The first 83 are the same across all Midland radios, but if you pick code 99 on your MXT105, most other radios won't be able to choose settings that allow them to hear you.

Feedback and Sources

I only have a couple of FRS/GMRS radios to test with, so most of this material has been pieced together using the online owners manuals provided by the various radio manufacturers. If you have any ability to verify these charts using your own equipment, I'd love to hear from you. Especially if you have a Baofeng GMRS-V1 radio. Email correspondence, suggestions, corrections, or complaints to jared@k0tfu.org.

This page was inspired by work originally done by Harold Melton KV5R. Unfortunatly, his original link no longer works and I can't seem to find a replacement page on his site.

Updated 13 Dec 2019 to include Backcountry Access Link radios based on information received from Eric KI7WJP. He owns one of these radios, and verified the privacy codes are numbered the same way as Motorola.

Thanks to Fred E for confirming Baofeng GMRS-V1 CTCSS frequencies.

Thanks to Jared S for confirming Baofeng GMRS-V1 DCS and CTCSS interoperability with a Motorola T600 using these charts.

I've collected all my data in this Google Sheet, including the simplified tables published in this post. I used Tableizer to create HTML tables because embedded Google Sheets look really terrible.

Owners Manuals

Other Sources