Squawk Codes Explained: 1200, 7500, 7600, 7700

The four-digit codes on your transponder — what 1200 means, how a discrete code gets assigned, and the three codes you never want to need. · 5 min read

Every airplane with a transponder broadcasts a four-digit "squawk" code that tags you on a controller’s radar scope. The code itself is just an identifier — four digits, each from 0 to 7 (the transponder is octal, which is why you will never see an 8 or 9). Most of the time you are either squawking a standard VFR code or a discrete code that ATC assigned you. A small handful of codes are reserved for emergencies and are effectively off-limits for everyday use, because dialing one — even by accident while spinning the knobs past it — lights up alarms in a radar facility. Understanding the everyday codes and respecting the emergency ones is basic airmanship.

The everyday codes

1200 — VFR, not receiving ATC services. This is your default squawk any time you are just flying around VFR without flight following. If nobody has assigned you a code, you are on 1200.
A discrete code (for example 0412) — a unique code ATC assigns you when you request flight following or enter airspace where they are working you. When they give it to you, read it back and set it in the transponder.

When you switch your transponder to a discrete code, ATC’s computer ties that code to your callsign, so your data block (callsign, altitude, groundspeed) appears next to your target on their scope. That is why picking up flight following starts with a squawk code assignment.

Ident

Sometimes ATC needs to confirm which blip is you, and they will ask you to "ident." Ident is a button on the transponder — pressing it makes your radar target flash brightly for a few seconds so the controller can pick you out. It is an action, not a spoken code; you press the button and briefly acknowledge:

📻 ATC says “Skyhawk Five-Two-Kilo, squawk 0412 and ident.”

🎙 You say “Squawk 0412, ident, Five-Two-Kilo.”

Set the code, then press the IDENT button once. Do not press it repeatedly.

The three emergency codes

Three codes are reserved for emergencies. Learn them so you can both use them if you ever need to and — just as importantly — avoid rolling through them by accident when changing codes:

7500 — hijacking / unlawful interference. This one summons a very serious response; never dial it as a placeholder or a joke.
7600 — lost communications (radio failure). See the lost-comms guide for the full playbook.
7700 — general emergency. When you declare an emergency, squawking 7700 flags you to every facility in radar range.

A note on changing codes: when ATC gives you a new code, spin the knobs deliberately so you do not momentarily park on 7500, 7600, or 7700. Many modern transponders let you enter the whole code before it goes active, which avoids the problem entirely.

💡 The classic memory aid for the emergency codes: "seven-five, taken alive" (hijack), "seven-six, radio’s in a fix" (comms), "seven-seven, going to heaven" (emergency). Crude, but you will never forget them.

💡 The only way this becomes automatic is saying it out loud, dozens of times, before you key a live mic. That is exactly what ATCpal is for — practice reading back an assigned squawk code and ident. Practice it free at atcpal.app.

Phraseology sourced from the FAA Aeronautical Information Manual (Change 3, effective 9 July 2026) and the Pilot/Controller Glossary. Check the AIM · Last reviewed 13 August 2026.

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