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:

You have GMRS or FRS radios from different manufacturers and you can't get them to talk to each other.
You have a GMRS radio that sets CTCSS or DCS codes directly (i.e. Cobra HH450, Baofeng GMRS-V1, Baofeng GMRS-50X1) and you want to communicate with other GMRS/FRS radios that use privacy codes.
You enjoy reading arcane radio related stuff.

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.

Channel	Frequency	FRS Power	GMRS Power
01	462.5625	2 W	5 W
02	462.5875	2 W	5 W
03	462.6125	2 W	5 W
04	462.6375	2 W	5 W
05	462.6625	2 W	5 W
06	462.6875	2 W	5 W
07	462.7125	2 W	5 W
08	467.5625	0.5 W	0.5 W
09	467.5875	0.5 W	0.5 W
10	467.6125	0.5 W	0.5 W
11	467.6375	0.5 W	0.5 W
12	467.6625	0.5 W	0.5 W
13	467.6875	0.5 W	0.5 W
14	467.7125	0.5 W	0.5 W
15	462.5500	2 W	50 W
16	462.5750	2 W	50 W
17	462.6000	2 W	50 W
18	462.6250	2 W	50 W
19	462.6500	2 W	50 W
20	462.6750	2 W	50 W
21	462.7000	2 W	50 W
22	462.7250	2 W	50 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 works great for a ham operator like me, but may be overwhelming for many who purchase these radios. So 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:

Cobra
Midland
Motorola
Uniden
Backcountry Access
Rocky Talkie - versions sold after July 16th 2020

Freq (Hz)	Common	Cherokee 465	Motorola Sport	Radio Shack	Retevis RB15
67.0	1	1		1	1
69.3		2
69.4				2
71.9	2	3		3	3
74.4	3	4		4	4
77.0	4	5	A	5
79.7	5	6		6
82.5	6	7		7
85.4	7	8		8
88.5	8	9	B	9
91.5	9	10		10
94.8	10	11		11	11
97.4	11	12	C	12
100.0	12	13		13
103.5	13	14		14
107.2	14	15	D	15
110.9	15	16		16
114.8	16	17		17
118.8	17	18	E	18
123.0	18	19		19
127.3	19	20	F	20
131.8	20	21		21
136.5	21	22	G	22
141.3	22	23		23
146.2	23	24		24
151.4	24	25		25
156.7	25	26		26	26
159.8		27		27
162.2	26	28		28	28
165.5				29
167.9	27	29		30	30
171.3				31
173.8	28	30		32	32
177.3				33
177.8
179.9	29	31		34	34
183.5		32		35
186.2	30	33		36	36
189.9		34		37
192.8	31	35		38	38
196.6		36
199.5		37
203.5	32	38			41
206.5		39
210.7	33	40			43
218.1	34	41			44
225.7	35	42			45
229.1		43
233.6	36	44			47
241.8	37	45			48
250.3	38	46			49
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:

Backcountry Access
Motorola
Uniden
Rocky Talkie - versions sold after July 16th 2020

DCS Code	Baofeng GMRS-V1	Common	Cobra	Midland	Retevis RB15
023	D023N	39	1	1	1
025	D025N	40	2	2	2
026	D026N	41	3	3
031	D031N	42	4	4
032	D032N	43	5	5	5
036	D036N			84
043	D043N	44	6	6	7
047	D047N	45	7	7	8
051	D051N	46	8	8	9
053	D053N			85
054	D054N	47	9	9	11
065	D065N	48	10	10	12
071	D071N	49	11	11	13
072	D072N	50	12	12	14
073	D073N	51	13	13	15
074	D074N	52	14	14	16
114	D114N	53	15	15	17
115	D115N	54	16	16	18
116	D116N	55	17	17	19
122	D122N			86
125	D125N	56	18	18	21
131	D131N	57	19	19	22
132	D132N	58	20	20	23
134	D134N	59	21	21	24
143	D143N	60	22	22	25
145	D145N			87
152	D152N	61	23	23	27
155	D155N	62	24	24	28
156	D156N	63	25	25	29
162	D162N	64	26	26	30
165	D165N	65	27	27	31
172	D172N	66	28	28	32
174	D174N	67	29	29	33
205	D205N	68	30	30	34
212	D212N			88
223	D223N	69	31	31	36
225	D225N			89
226	D226N	70	32	32	38
243	D243N	71	33	33	39
244	D244N	72	34	34	40
245	D245N	73	35	35	41
246	D246N			90
251	D251N	74	36	36	43
252	D252N			91
255	D255N			92
261	D261N	75	37	37	46
263	D263N	76	38	38	47
265	D265N	77	39	39	48
266	D266N			93
271	D271N	78	40	40	50
274	D274N			94
306	D306N	79	41	41	52
311	D311N	80	42	42	53
315	D315N	81	43	43	54
325	D325N			95
331	D331N	82	44	44	56
332	D332N			96
343	D343N	83	45	45	58
346	D346N	84	46	46	59
351	D351N	85	47	47	60
356	D356N			97
364	D364N	86	48	48	62
365	D365N	87	49	49	63
371	D371N	88	50	50	64
411	D411N	89	51	51
412	D412N	90	52	52
413	D412N	91	53	53
423	D423N	92	54	54
431	D431N	93	55	55
432	D432N	94	56	56
445	D445N	95	57	57	71
446	D446N			98
452	D452N			99
454	D454N			100
455	D455N			101
462	D462N			102
464	D464N	96	58	58	77
465	D465N	97	59	59
466	D466N	98	60	60
503	D503N	99	61	61
506	D506N	100	62	62
516	D516N	101	63	63	82
523	D523N			103
526	D526N			104
532	D532N	102	64	64	85
546	D546N	103	65	65
565	D565N	104	66	66
606	D606N	105	67	67
612	D612N	106	68	68
624	D624N	107	69	69
627	D627N	108	70	70
631	D631N	109	71	71
632	D632N	110	72	72	93
645	D645N
654	D654N	111	73	73	95
662	D662N	112	74	74
664	D664N	113	75	75
703	D703N	114	76	76
712	D712N	115	77	77	99
718
723	D723N	116	78	78	100
731	D731N	117	79	79
732	D732N	118	80	80	102
734	D734N	119	81	81
743	D743N	120	82	82	104
754	D754N	121	83	83	105

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 will have to disable privacy codes in order to hear you.

Hopefully this helps make sense of the sometimes confusing so-called privacy codes on FRS and GMRS radios. If your radio isn't listed here or if you can confirm or dispute any information on this page, I'd love to hear from you. Email correspondence, suggestions, corrections, or complaints to jared@k0tfu.org.

Changelog

9 Jun 2021

Add Retevis RB15 CTCSS and DCS mappings provided by Tom B.
Add Rockie Talkie mapping confirmed by Tom B.
Add the Wayback Machine link to Harold Melton's original page. Thanks to Tim W for the link.

13 Dec 2019

Add 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.

Feedback and Sources

This page was inspired by work originally done by Harold Melton KV5R. Unfortunately, his original link no longer works and I can't seem to find a replacement page on his site. However, his page is preserved by the The Wayback Machine.

I only have a couple of FRS/GMRS radios to test with and the original version of this article was mostly pieced together from owners manuals. Since then several people have written with additional information on new radios and tests with their own equipment. Thanks to everyone who had contributed.

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.

Contributors

Fred E for confirming Baofeng GMRS-V1 CTCSS frequencies.
Jared S for confirming Baofeng GMRS-V1 DCS and CTCSS interoperability with a Motorola T600 using these charts.
David M for confirming the Midland X-Talker T290 matches the tables in this article.
Tim W for the Wayback Machine link to Harold Melton's original page.
Eric KI7WJP for providing verified Backcountry Access CTCSS and DCS codes.
Tom B for confirming Retevis RB15 and Rockie Talkie codes and providing links to owners manuals.

Owners Manuals

Backcountry Access Link 2.0 Manual which contains no useful information about their privacy codes, not even if they use CTCSS or DCS.

Jetstream JT270M Manual

Motorola MT Series Users Guide which doesn't contain a CTCSS or DCS chart (boo).
Motorola T600 Series User Manual
Motorola TLKR T8 Manual which has Motorola's map of CTCSS tones and DCS codes to their "sub-codes"

Rocky Talkie

Other Sources