An SSR code allocation is not a simple task since there is a multitude of rules that define the availability of codes to be used, depending on the origin of the flight, the station that is assigning the code, destination of the flight, the ATC equipment available, among others.
On our Airspace, the allocation is made accordingly to the EUROCONTROL SSR CAL.

 

You can find a simplified version of the document, for Portuguese Airspace below.
It is organized between Domestic, Departures, Arrivals and Transit. On each category you can find the different code blocks and the correspondent designation used on IVAC2.
Please note that the SSR Code Allocation for Arrivals and Transit shall only be done if the aircraft is inbound from an uncontrolled airspace.

Domestic Flights

Origin – LP
Destination – LP

Between 0020 and 0027 – Domestic 002X

Between 0030 and 0037 – Domestic 003X

Between 3201 and 3277 – Domestic 32XX

International Departures

Origin – LP
Destination – ALL

Between 3301 and 3377 – INT DEP 1

Between 4701 and 4777 – INT DEP 2

Between 5401 and 5477 – INT DEP 3

Arrival and Transit Flights

Origin – LF
Destination – LP

Between 7601 and 7677 – INB FM LF


Origin
– LECM
Destination – ALL

Between 1401 and 1477 – INB FM LECM


Origin
– ED
Destination – ALL

Between 2501 and 2577 – INB FM ED


Origin
– EY/EP/LB/LO/LU/LY/UK
Destination – ALL

Between 2201 and 2277 – CCAMS


Origin
– ALL others
Destination – ALL

Between 4401 and 4477 – TRANSIT

Origin – EE/EF/EG/EI/EK/EN/ES
Destination – LP

Between 7701 and 7717 – CCAMS INB


Origin
 – EH
Destination – ALL

Between 2101 and 2177 – INB FM EH


Origin
 – GM
Destination – ALL

Between 6401 and 6477 – INB FM GM


Origin
 – DA/GC/LE
Destination – ALL

Between 4701 and 4777 – DA GC LE