Use of Callsigns and Suffixes

Call signs

The purpose of call signs

Call signs are the primary method amateurs use to identify themselves when communicating with
other operators. Each amateur radio licensee has a unique call sign, by which they can be identified.
This is important for spectrum management as it enables receiving stations to know who is calling
them and so ensures compliance with relevant international agreements and identification of the
source of any problematic signals.

Acceptable call sign formats

The call signs that Ofcom issues for normal operation under the Amateur Radio Licence are made up of an initial character ‘G’ or ‘M’ (denoting that a station is authorised by the UK), followed by a
number and then, normally, three letters. Very old call signs, some of which remain in use, have only two trailing letters. A call sign with only two trailing letters or which starts with ‘G2’ is only available if the applicant previously held it.
The call signs that Ofcom issues for normal operation under the Amateur Radio Licence for Full
(Club) Licences are made up of an initial character ‘G’, followed by three letters. Some club call signs have only two trailing letters if the club can prove the call sign heritage and connection to the Club.
The call sign that ofcom issue shows the level of the station, as set out in the table below.

Amateur Radio Call sign formats

Assigning call signs

When applying online, you are able to choose the call sign suffix (trailing three letters) that you wish to use. The prefix (e.g., for Foundation, ‘M7’) is already designated. There is also the option to choose the next available call sign if you have no preferences.
If you wish to obtain a specific call sign outside of the blocks currently being issued (e.g., Foundation, ‘M7’), you may manually send in a request to Ofcom with your preferences, and they will look to see how they can accommodate your request.
Lists of available call signs are not routinely published by Ofcom, but when requesting a call sign, it is important to consider if it is permitted with your licence level and acceptable call-sign formats.
Currently, we do not allow individuals to change their call sign if allocated one they don’t like online.

Using a Regional Secondary Locator (RSL)

A RSL enhances the ‘core’ call sign of an Amateur Radio Licence. They are used to indicate the UK nation (or Crown Dependency) in which a station is operating. The use of RSL’s, in most cases, is now optional for licensees. The licence does not require the use of an RSL except in the case of Intermediate stations that utilise a ‘2’ format call sign. This is because, without an RSL, the format of these call signs (e.g., ‘20aaa’) does not confirm to the requirements set out in the Radio Regulations. Inserting the RSL ensures that the call sign does confirm to the Radio Regulations.
RSL’s are not mandated by the Radio Regulations and are used by few other countries and serve no
spectrum management purposes, hence they are no longer a mandatory requirement. However, we understand that RSLs are important to some radio amateurs and therefore, they can continue to be
used in call signs, on an optional basis.

UK Regional Secondary Locators (RSL)

Region	All Licences	Full (Club) Licence only
England	E	X
Guernsey	U	P
Isle Of Man	D	T
Jersey	J	H
Nothern Ireland	I	N
Scotland	M	S
Wales	W	C

Suffixes

A ‘suffix’ is a group of one or more letters added to the end of a call sign following the ‘slash’ (‘/’)
character. These have typically been used to indicate that the station is not at its main station
address. Examples of suffixes that can be used to indicate an alternative location are ‘/A’, ‘/M’,
‘/MM’, ‘/P’, ‘/AM’. Any suffix, following the ‘slash’ (‘/’) symbol may be added to the transmitted call sign, so long as the station remains identifiable. Suffixes are not mandated by, or referenced in, the amateur radio licence as they do not form part of the ‘core’ call sign and are not required for the management of the radio spectrum. When used, the suffix becomes part of the call sign and is therefore subject to the Wireless Telegraphy (Content of Transmission) Regulations, 1988 which must be complied with at all times; any breach of these regulations could be considered a police matter and will be referred to the correct authorities as appropriate.

Suffix	Meaning	Usage Examples
/A	Alternative	Used at a diffrent static address (Hotel/Friends House)
/M	Mobile	Driving round in a vehicle
/MM	Mobile Marine	Whilst on a vessel on the water, check licence conditions
/AM	Aeronautical Mobile	Whilst airborne, restricted licences only
/P	Portable	Whilst out walking with a handheld