# When replying to ATC, callsign first or last?

When I was in flight school, some instructor told me that it is the unknown ICAO standard that you should reply to an ATC call with your callsign first, like this:

"XYZ123, climb FL350"
- "XYZ123, climb FL350"


But I only know one airline that operates like this. In all other parts of the world, I hear:

"XYZ123, climb FL350"
- "Climb FL350, XYZ123"


So can someone tell me the definite ICAO standard on that and where it is written down?

• Standard aside, I think it is important to do what everyone else is doing. It makes your response align with what controllers and other pilots expect. – kevin Apr 12 '18 at 15:17
• I have no idea what ICAO says, but the FAA says "either at the beginning or at the end of your transmission" (AIM 4-2-3(c)). – Pondlife Apr 12 '18 at 15:18
• @Pondlife, do you have a link? – Ulu83 Apr 12 '18 at 15:20
• – Pondlife Apr 12 '18 at 16:04

### ICAO Annex 10 - Aeronautical Telecommunications Vol 2

• When replying, you end the message with the call sign.

5.2.1.9.2.2 PANS.— An aircraft station should acknowledge receipt of important air traffic control messages or parts thereof by reading them back and terminating the readback by its radio call sign.

Note 1.— Air traffic control clearances, instructions and information requiring readback are specified in PANS-ATM (Doc 4444).

Exception to rule:

5.2.4.4.1 PANS.— When an aeronautical station initiates a call by SELCAL, the aircraft replies with its radio call sign, followed by the phrase “GO AHEAD”.

However, local procedures should be followed if they are different. See the post, 'Is it bad practice to say my callsign first in a transmission to ATC?' for an answer about UK and Germany. Basically when replying you finish with the c/s, when requesting you begin with the c/s.

• Supposedly, the reason for saying the callsign last is that if two aircraft transmit at the same time, the callsign for one party (whoever talks longer) will be readable. ATC can then ask that aircraft to say again, deal with them, and then inquire for "other aircraft calling". – StephenS Mar 5 '19 at 0:22

The standard procedure for a pilot:

1. Who do I want to talk to?
2. Who am I?
3. Where am I? (not necessarily needed after initial contact)
4. What do I want?


After initial contact, some of the requirements may be ignored when back and forth communication is happening, without other airplanes talking to that ATC.

For read back, it is needed that the pilot repeats the instruction to clarify. The call sign can be at the end for confirmation.

An example of that is here:

Controller: Callsign, climb (descend) and maintain new altitude
Pilot: Climb (descend) and maintain new altitude, callsign