CB channels in Australia legal channel designations

27MHz CB

27MHz or HF CB is possibly best known from movies such as Smokey and the Bandit and Convoy. This band utilises equipment with 40, 23 and 18 channels. 18 channels (known as “Australian”) was the original allocation legalised in 1977, while 40 channels was the band legalised when the class licence was introduced and was the same as the 40 channels used in the USA at the time. 23 channels was used in the USA at the time of legalisation in Australia and, although illegal, was used in Australia prior to 1977. 23 channel sets use the first 23 channels of the 40 channel allocation.

* Note:

With the exception of channels designated for a specific mode/use (e.g. call channels), the modes (AM/FM/SSB) shown under “Modes/Use” are by way of a “gentleman’s agreement” that came in before CB was legalised (and inherited from the USA). Other than the call channels (11 and 16), any mode can legally be used on any channel; however, in the interests of peaceful coexistence between AM/FM and SSB operators, the band plan shown is strongly suggested. Also, the frequency does not always match the channel number until channel 25 and above, and the frequencies for channels 23 and 24 are out of sequence due to early equipment design.

Also note, the 2025 class licence removed the need for call channels, but retained the restriction of AM and LSB on channels 11 and 16, respectively, likely due to their ongoing use by agreement as call channels. FM was also introduced in the 2025 class licence.

Ch. (23/40)	Ch. (18)	Frequency	Use (legal)	Modes/Use*
1	—	26.965	General use	AM/FM
2	—	26.975	General use	AM/FM
3	—	26.985	General use	AM/FM
4	—	27.005	General use	AM/FM
5	1	27.015	General use	AM/FM
6	2	27.025	General use	AM/FM
7	3	27.035	General use	AM/FM
8	4	27.055	General use	AM – Road channel
9	5	27.065	EMERGENCY	AM/FM/SSB
10	—	27.075	General use	AM/FM
11	6	27.085	Calling (AM)*	AM only
—	7	27.095	WITHDRAWN	Not used
12	8	27.105	General use	AM/FM
13	9	27.115	General use	AM/FM
14	10	27.125	General use	AM/FM
15	11	27.135	General use	SSB
16	12	27.155	Calling (LSB)*	SSB
17	13	27.165	General use	SSB
18	14	27.175	General use	SSB
19	15	27.185	General use	SSB
—	16	27.195	WITHDRAWN	Not Used
20	17	27.205	General use	SSB
21	—	27.215	General use	SSB
22	18	27.225	General use	SSB
23	—	27.245	General use	SSB
24	—	27.235	General use	SSB
25	—	27.255	General use	SSB
26	—	27.265	General use	SSB
27	—	27.275	General use	SSB
28	—	27.285	General use	SSB
29	—	27.295	General use	SSB
30	—	27.305	General use	SSB
31	—	27.315	General use	SSB
32	—	27.325	General use	SSB
33	—	27.335	General use	SSB
34	—	27.345	General use	SSB
35	—	27.355	General use	LSB long distance calling
36	—	27.365	General use	SSB
37	—	27.375	General use	SSB
38	—	27.385	General use	SSB
39	—	27.395	General use	SSB
40	—	27.405	General use	SSB