Table of Contents
UK Squawk List (WIP)
There are many sources for squawk codes in the UK on the internet, but a lot of them seem to be based on older lists/information. So, here's the most up-to-date list direct from the UK's Civil Aviation Authority documentation. We'll try and keep this up to date as the documentation is usually updated every month, but actual changes will be rare. Anchor links are provided in the dropdown menu to each block section.
Squawk codes can be useful for determining where something has come from or is going to in the case of missing or incomplete route information. Or they can identify a specific type of mission or what an aircraft is up to. The emergency squawks are also listed here - these will trigger alerts live on the emergencies table on the tracker website and also hopefully soon into the ADS-B channel on the OARC Discord. Also remember that each digit is an octal - meaning 0-8 - so you'll never see a 9 anywhere.
Edit 16/05/24 You can now expect alerts to Discord ONLY regarding NATO Quick Reaction Alerts - fun!
There are a lot of accompanying notes that go with this data and these are reproduced here, although some are operational rather than informational. There are also a few extra notes added by us into places to try and help non-aviation-industry types actually understand things, as well as links to useful glossary terms or further sources of information:
Glossary of terms
WIP
Notes for the list below
| Note 1: Pilots are not to preselect Mode A code settings for discrete codes until instructed to do so by the appropriate controlling agency. |
| Note 2: The codes or series annotated * are used for conspicuity, co-ordination or special purposes and, unless procedures have been agreed with UK CAA Safety and Airspace Regulation Group, the Mode A code and associated Mode C pressure-altitude reporting data must be considered unvalidated and unverified. |
| Note 3: These codes are assigned by Aberdeen for helicopters operating in Northern North Sea Off-shore area and out to 5° West. |
| Note 4: Ground based transponder equipment. |
| Note 5: This code is allocated to Transit (ORCAM) UK and is temporarily assigned for use by London Control (Swanwick) FIS. Notwithstanding, it retains all the properties and protection of an ORCAM Transit code. |
| Note 6: These codes will be assigned to aircraft on air policing missions within the UK FIR/UIR operating under Air Defence Priority Flight (ADPF) status. NATO Air Surveillance and Control System (ASACS) units, NATO Airborne Early Warning aircraft or military ATCCs will normally control the aircraft. The actual controlling unit for a particular flight will be notified by the relevant NATO ASACS unit to the military ATC supervisor whose area of responsibility contains the intended route of the ADPF aircraft. The military ATC supervisor will then inform the relevant civil ATCC. Where any doubt about the controlling agency exists, the relevant military ATC supervisor with the responsibility for the area within which the ADPF aircraft is operating should be contacted in the first instance. |
| Note 7: This code is assigned by the FISO to aircraft requesting entry into Controlled Airspace for the purpose of joining or crossing the ATS Route network. Pilots shall only select the code when they are within two-way communication with the London FIS. Where available, the Mode C pressure-altitude reporting mode of the transponder should also be selected. If communication is lost or the aircraft leaves the FIS frequency, pilots shall deselect this special purpose code. The assignment of this code does not imply the provision of a radar service and the code and any associated Mode C pressure-altitude reporting data must be considered to be unvalidated and unverified. |
| Note 8: All Spadeadam squawks indicating flight above FL 50 will be validated and verified by Spadeadam ATC. |
| Note 9: This conspicuity code shall be used by aircraft operating in an Off-shore Safety Area (OSA) when contact with the Area Air Traffic Service Provider (ATSP) has not been established and no other code has previously been allocated. |
| Note 10: These codes will be assigned to Unmanned Aeronautical Vehicles operating within an active danger area, which will be validated but may be unverified. |
| Note 11: Aircraft operating within, and in the vicinity of, EGD123, EGD124, EGD125, EGD126, EGD128 (these are specific danger areas). |
| Note 12: This conspicuity code shall be used by Unmanned Aerial Systems/Remotely Piloted Aircraft that have lost communications with their remote pilot and are following a pre-programmed Lost Link flight profile. |
| Note 13: This code may also be used for Blackpool Instrument Training. |
| Note 14: For use within a 20 NM radius of Land’s End up to 4000 FT AMSL. |
| Note 15: Codes allocated to HQ Air Command are reserved for the purpose of major Operations or Exercises under HQ Air Command control including national events coordinated under HQ 11 Gp. |
| Note 16: Codes “On loan to CCAMS” may be reallocated to Special Events (e.g. Royal International Air Tattoo) providing at least two weeks' notice is submitted to *CAA email address removed*. |
Squawk List by Block
0XXX
| Codes/Series | Controlling Authority/Function |
| 0000 | SSR data unreliable |
| * 0001 | Height Monitoring Unit (See note 4) |
| * 0002 | Ground Transponder Testing (Refer to ENR 1.6, paragraph 2.2.3) |
| * 0003 | Surrey/Sussex HEMS (HLE60) |
| 0004-0005 | Scottish Non-standard Flights |
| * 0006 | British Transport Police ASU |
| * 0007 | Off-shore Safety Area (OSA) Conspicuity (See note 9) |
| * 0010 | This code may be used when flying in the vicinity of Birmingham, operating outside of Birmingham CTR/ Birmingham CTA and monitoring Birmingham Radar frequency (Refer to ENR 1.6, paragraph 2.2.5) |
| * 0011 | Aircraft operating in the vicinity of Bournemouth Control Zone and monitoring Bournemouth Radar Frequency West (Refer to ENR 1.6, paragraph 2.2.5) |
| * 0012 | This code may be used when flying in the vicinity of London City and London Heathrow and monitoring Thames Director frequency (Refer to ENR 1.6, paragraph 2.2.5) |
| * 0013 | This code may be used when flying in the vicinity of London Luton and monitoring Luton Radar frequency (Refer to ENR 1.6, paragraph 2.2.5) |
| * 0014 | Kent Air Ambulance (HLE21) |
| * 0015 | Essex Air Ambulance (HLE07) |
| * 0016 | Thames Valley Air Ambulance (HLE24) |
| * 0017 | London Air Ambulance (HLE27) |
| * 0020 | Air Ambulance Helicopter Emergency Medivac |
| * 0021 | Fixed-wing aircraft (Receiving service from a ship) |
| * 0022 | Helicopter(s) (Receiving service from a ship) |
| * 0023 | Aircraft engaged in actual SAR Operations |
| * 0024 | Radar Flight Evaluation/Calibration (Refer to ENR 1.6, paragraph 2.2.2.2) |
| 0025 | Scottish Non-standard Flights |
| * 0026 | Special Tasks |
| * 0027 | London Control (Swanwick) Ops Crossing/Joining CAS (See note 7) |
| * 0030 | FIR Lost |
| * 0031 | Hertfordshire Air Ambulance (HLE55) |
| * 0032 | Aircraft engaged in police air support operations |
| * 0033 | Aircraft Paradropping (Refer to ENR 1.6, paragraph 2.2.2.2) |
| * 0034 | Antenna trailing/target towing/glider towing |
| * 0035 | Selected Flights - Helicopters |
| * 0036 | Helicopter Pipeline/Powerline Inspection Flights |
| * 0037 | Royal Flights - Helicopters |
| * 0040 | Civil Helicopters North Sea |
| * 0041-0061 | Police Air Support |
| 0062-0077 | No 1 Air Control Centre |
| * 0100 | HQ Air Command (See note 15) |
| 0101-0117 | Transit (ORCAM) Brussels |
| 0120-0137 | Transit (ORCAM) Germany |
| 0140-0177 | Transit (ORCAM) Amsterdam |
| * 0200 | HQ Air Command (See note 15) |
| 0201-0277 | Allocated to NATS as CCAMS redundancy |
| * 0300 | HQ Air Command (See note 15) |
| 0301-0377 | Assigned by CCAMS |
| * 0400 | HQ Air Command (See note 15) |
| * 0401 | RAF Leeming Conspicuity |
| 0401-0417 | Birmingham Radar |
| 0401-0437 | Ireland Domestic |
| 0401-0450 | Exeter Approach |
| 0401-0461 | RAF Lakenheath |
| 0402-0437 | RAF Leeming |
| * 0420 | Coventry Conspicuity |
| 0421-0427 | Farnborough Zone/Approach Radar IFR/SVFR |
| * 0430 | Hawarden Airport Conspicuity Code |
| 0430-0437 | Edinburgh Approach |
| 0430-0456 | Farnborough LARS West |
| 0431-0446 | Hawarden Approach |
| * 0440 | This code may be used when flying in the vicinity of Edinburgh, operating outside of Edinburgh CTR/ Edinburgh CTA and monitoring Edinburgh Radar frequency (Refer to ENR 1.6, para 2.2.5) |
| 0441-0443 | Edinburgh Approach |
| * 0450 | Blackpool Basic Service Conspicuity |
| * 0451 | Blackpool Procedural Service Conspicuity (See note 13) |
| * 0452 | Morecambe Bay Helicopter Conspicuity |
| * 0453 | Liverpool Bay Helicopter Conspicuity |
| 0455 | Ekofisk RMZ |
| * 0457 | Farnborough LARS West VFR Conspicuity Code for periods when no discrete SSR code is available |
| 0460-0467 | Farnborough Zone VFR |
| * 0462-0467 | USAFE autonomous use in EGD323 complex (another specific danger area) and Vale of York AIAA. |
| 0470-0477 | Allocated to NATS as CCAMS redundancy |
| * 0500 | HQ Air Command (See note 15) |
| 0501-0577 | Assigned by CCAMS |
| * 0600 | HQ Air Command (See note 15) |
| 0601-0637 | Transit (ORCAM) Germany |
| 0640-0677 | Transit (ORCAM) Paris |
| * 0700 | HQ Air Command (See note 15) |
| 0701-0727 | Transit (ORCAM) Maastricht |
| 0730-0767 | Assigned by CCAMS |
| 0770-0777 | Transit (ORCAM) Maastricht |
1XXX
| Codes/Series | Controlling Authority/Function |
| 1000 | IFR GAT flights operating in designated Mode S Airspace |
| 1001-1067 | Transit (ORCAM) Spain |
| 1070-1077 | Assigned by CCAMS |
| * 1100 | HQ Air Command (See note 15) |
| 1101-1137 | Transit (ORCAM) Germany |
| 1140-1176 | Assigned by CCAMS |
| * 1177 | London Control (Swanwick) FIS (Refer to ENR 1.6, paragraph 2.2.2.2 and note 5) |
| * 1200 | HQ Air Command (See note 15) |
| 1201-1247 | Channel Islands Domestic |
| 1250-1257 | Assigned by CCAMS |
| 1260-1277 | Queen Elizabeth Class aircraft carrier operations |
| * 1300 | HQ Air Command (See note 15) |
| * 1301-1306 | Assigned by CAA |
| 1307-1327 | NATO - Air Policing (Air Defence Priority Flights) (See note 6) |
| 1330-1377 | Transit (ORCAM) Germany |
| * 1400 | HQ Air Command (See note 15) |
| 1401-1407 | Irish CCAMS Contingency Codes |
| 1410-1477 | Assigned by CCAMS |
| * 1500 | HQ Air Command (See note 15) |
| * 1501-1577 | Battlespace Management Force HQ |
| * 1600 | HQ Air Command (See note 15) |
| * 1601-1677 | Battlespace Management Force HQ |
| * 1700 | HQ Air Command (See note 15) |
| * 1701-1727 | Battlespace Management Force HQ |
| 1730-1746 | Newquay Approach |
| 1730-1746 | Farnborough LARS East |
| * 1730-1767 | RAF Spadeadam (See note 8) |
| 1730-1776 | RAF Coningsby |
| * 1747 | Farnborough LARS East Conspicuity |
| * 1747 | Newquay Conspicuity |
| 1750-1757 | Farnborough Zone (IFR/SVFR) |
| 1750-1756 | Newquay Approach |
| * 1757 | Newquay LARS when no discrete SSR code is available |
| 1760-1777 | RNAS Yeovilton Fighter Control |
| * 1777 | RAF Coningsby Conspicuity |
2XXX
| Codes/Series | Controlling Authority/Function |
| * 2000 | Conspicuity when entering United Kingdom airspace from an adjacent region where the operation of transponders has not been required; or when operating within United Kingdom airspace in accordance with IFR and is either not receiving an ATS or has not received a specific instruction from ATS concerning the setting of the transponder; or unless instructed otherwise by ATS, Mode S transponder equipped aircraft on the aerodrome surface when under tow, or parked and prior to selecting Off or STBDY. (Refer to ENR 1.6, paragraphs 2.2.1 e and 2.2.2.1.3) |
| 2001-2077 | Assigned by CCAMS |
| * 2100 | HQ Air Command (See note 15) |
| 2101-2147 | Transit (ORCAM) Amsterdam |
| 2150-2177 | Assigned by CCAMS |
| * 2200 | HQ Air Command (See note 15) |
| 2201-2277 | Assigned by CCAMS |
| * 2300 | HQ Air Command (See note 15) |
| 2301-2377 | Transit (ORCAM) France |
| * 2400 | HQ Air Command (See note 15) |
| * 2401-2477 | Battlespace Management Force HQ |
| * 2500 | HQ Air Command (See note 15) |
| 2501-2577 | Transit (ORCAM) Germany |
| * 2600 | HQ Air Command (See note 15) |
| 2601-2617 | Glasgow Approach |
| 2601-2637 | RAF Cranwell |
| 2601-2645 | MoD Boscombe Down |
| 2601-2657 | Irish Domestic Westbound departures and Eastbound arrivals |
| * 2620 | This code may be used when flying in the vicinity of Glasgow, operating outside of Glasgow CTR/ Glasgow CTA and monitoring Glasgow Radar frequency (Refer to ENR 1.6 para 2.2.5) |
| 2621-2630 | Aberdeen (Sumburgh Approach) |
| 2631-2637 | Aberdeen (Northern North Sea Off-shore) (See note 3) |
| 2640-2642 | RAF Cranwell - Lincolnshire AIAA |
| 2640-2657 | Aberdeen (Northern North Sea Off-shore - Sumburgh Sector) (See note 3) |
| 2643-2644 | RAF Cranwell |
| * 2645 | RAF Cranwell Conspicuity |
| 2646-2647 | RAF Cranwell |
| 2646-2647 | MoD Boscombe Down - UAS |
| * 2650 | MoD Boscombe Down Conspicuity |
| 2650-2653 | Leeds Bradford Approach |
| 2651-2657 | MoD Boscombe Down |
| * 2654 | Leeds Bradford Conspicuity |
| 2655-2676 | Leeds Bradford Approach |
| * 2660 | Thruxton conspicuity |
| 2660-2677 | Aberdeen (Northern North Sea Off-shore) (See note 3) |
| 2661-2675 | Middle Wallop |
| * 2676 | Middle Wallop Conspicuity |
| 2677 | Middle Wallop Conspicuity |
| * 2677 | This code may be used when flying in the vicinity of Leeds Bradford and monitoring the Leeds Radar Frequency (Refer to ENR 1.6, para 2.2.5) |
| * 2700 | HQ Air Command (See note 15) |
| 2701-2737 | Assigned by CCAMS |
| 2740-2777 | Transit (ORCAM) Zurich |
3XXX
| Codes/Series | Controlling Authority/Function |
| 3000 | NATO Aircraft receiving a service from AEW aircraft |
| 3001-3077 | Transit (ORCAM) Zurich |
| 3100 | NATO Aircraft receiving a service from AEW aircraft |
| 3101-3127 | Transit (ORCAM) Germany |
| 3130-3177 | Transit (ORCAM) Amsterdam |
| 3200 | NATO Aircraft receiving a service from AEW aircraft |
| 3201-3277 | Transit (ORCAM) Turkey - may also be Assigned by CCAMS |
| 3300 | NATO Aircraft receiving a service from AEW aircraft |
| 3301-3303 | Swanwick (Military) Special Tasks |
| 3304-3306 | Aircraft receiving a service from London D&D Cell |
| * 3307 | D&D Conspicuity Training Fix |
| 3310-3367 | Swanwick (Military) |
| 3370-3377 | Allocated to NATS as CCAMS redundancy |
| 3400 | NATO Aircraft receiving a service from AEW aircraft |
| 3401-3477 | Assigned by CCAMS |
| 3500 | NATO Aircraft receiving a service from AEW aircraft |
| 3501-3507 | Transit (ORCAM) Luxembourg |
| 3510-3537 | Assigned by CCAMS |
| 3540-3577 | Transit (ORCAM) Berlin |
| 3600 | NATO Aircraft receiving a service from AEW aircraft |
| 3601-3623 | RAF Benson |
| 3601-3632 | Scottish UK FIS Purposes |
| 3601-3634 | RAF Waddington |
| 3601-3647 | Jersey Approach |
| 3601-3657 | Cardiff Approach |
| * 3624 | RAF Benson Conspicuity |
| 3625-3627 | RAF Benson |
| * 3636 | This code may be used when flying in the vicinity of Cardiff, operating outside of Cardiff CTR/Cardiff CTA and monitoring Cardiff Approach frequency (Refer to ENR 1.6, para 2.2.5) |
| * 3637 | Wycombe Air Park Conspicuity. Not to be used outside 20 NM from the airfield. |
| 3640-3645 | RAF Odiham |
| 3640-3666 | RAF Marham |
| 3640-3677 | Aberdeen (Northern North Sea Off-shore) (See note 3) |
| 3641-3647 | BAE Systems Warton |
| * 3646 | RAF Odiham Conspicuity |
| 3646-3657 | Cardiff Approach |
| 3647-3653 | RAF Odiham |
| * 3650 | BAE Systems Warton Conspicuity |
| 3651-3657 | BAE Systems Warton |
| * 3660 | This code may be used when flying in the vicinity of Warton Aerodrome and monitoring Warton Radar frequency (Refer to ENR 1.6, para 2.2.5) |
| 3660-3665 | Solent Approach (Southampton) |
| 3661-3677 | BAE Systems Warton |
| * 3666 | Solent Radar Conspicuity |
| * 3667 | RAF Marham - FIS Conspicuity |
| 3667-3677 | Solent Approach (Southampton) |
| 3700 | NATO Aircraft receiving a service from AEW aircraft |
| 3701-3706 | Norwich Approach |
| 3707 | Norwich Basic Service |
| 3710 | Norwich Approach |
| * 3701-3717 | Military aircraft under service from RN AEW aircraft in South West Approaches |
| 3701-3736 | RAF Brize Norton |
| 3701-3727 | Guernsey Approach |
| 3701-3767 | RAF Lossiemouth |
| 3720-3727 | RAF Valley |
| 3720-3727 | RAF Wittering Approach/Director |
| 3720-3766 | Newcastle Approach |
| * 3727 | This code may be used when flying in the vicinity of RAF Brize Norton, operating outside of Brize Norton CTR and monitoring Brize Norton LARS frequency (Refer to ENR 1.6, paragraph 2.2.5) |
| 3730-3736 | RAF Valley |
| 3730-3747 | RAF Wittering Tutor Operations |
| * 3737 | RAF Valley - Visual Recovery |
| * 3737 | RAF Brize Norton Approach Conspicuity |
| * 3737 | This code may be used when flying in the vicinity of Newcastle, operating outside of Newcastle CTR and Newcastle CTA and monitoring Newcastle Radar frequency (Refer to ENR 1.6, para 2.2.5) |
| 3740-3745 | RAF Brize Norton |
| 3740-3747 | RAF Valley |
| * 3750 | RAF Wittering Zone Conspicuity (Basic Service) |
| 3750-3751 | RAF Valley GH |
| 3750-3761 | TC Gatwick |
| 3751-3757 | RAF Wittering Zone Transits |
| 3752 | RAF Valley - RIFA |
| * 3753 | RAF Valley - Low Level Helicopters |
| * 3754 | RAF Valley - Special Tasks |
| 3755 | RAF Valley Radar Practice Force Landing (RPFL) |
| 3756 | RAF Valley Straight In Practice Force Landing (SIPFL) |
| 3757 | RAF Valley Rotary at RAF Mona |
| 3760 | RAF Wittering |
| 3760-3765 | RAF Valley GH |
| 3761 | RAF Wittering – Cranwell/Wittering/Cranwell VFR Transit |
| * 3762 | Shoreham ATS IFR |
| 3762 | RAF Wittering |
| * 3763 | Shoreham ATS VFR |
| 3764-3766 | Gatwick Tower |
| * 3767 | Redhill Approach Conspicuity |
| * 3767 | Newcastle Approach Conspicuity |
| 3770-3777 | Western Radar |
4XXX
| Codes/Series | Controlling Authority/Function |
5XXX
| Codes/Series | Controlling Authority/Function |
6XXX
| Codes/Series | Controlling Authority/Function |
7XXX
| Codes/Series | Controlling Authority/Function |