SSR Code requests

Mode 3/A code allocation information

Regular allocations

SSR codes can be requested for prolonged use by air traffic control services or for aircraft identification.

We need the following information by email or post to start assessing the request:

  • Name of organisation requiring codes
  • Details of any codes already allocated to that organisation
  • Number of codes required
  • Details of preferred codes
  • Requirement for codes. For example, a Police Air Support Unit requesting a single code for discrete aircraft identification, or an ANSP requesting a set of codes for air traffic control
    • If requesting a code for discrete identification, the areas of operation of any aircraft wearing that code should be provided
    • If requesting codes for air traffic control, details of the current and future number of movements to be handled by the ANSP
  • Name and telephone contact details

The application and assessment process can take up to four months.

The allocation of a code or set of codes does not imply any right over its continued use and it may be necessary to withdraw or reallocate codes to effectively manage requirements.

Temporary allocations

SSR codes can also be requested for temporary allocation, for example for military exercises or civil aviation air shows.

Temporary requests should be submitted at least one month before the proposed use of the temporary code using the SSR NOTAM Application Form which can be posted or faxed to us.

There are a finite number of codes available so we cannot guarantee allocations.

Contact Details 

020 7453 6534
020 7453 6565 


Surveillance & Spectrum Management
Directorate of Airspace Policy
Civil Aviation Authority
CAA House
45-59 Kingsway