Your aircraft has a name on the radio—its callsign. This callsign is what identifies you to ATC and to other aircraft on the frequency. Radio communication is half-duplex, meaning everyone on the frequency hears everyone else. To be clear who you are addressing and who is being addressed, every transmission must include a callsign. The callsign is typically placed at the beginning of your transmission, except during readback, when it goes at the end.

There are three standard ways an aircraft is identified by callsign in European aviation:

Your aircraft has a registration mark—a tail number painted on the fuselage. This is assigned when the aircraft is first registered in a country and never changes. The registration consists of a country prefix (one or two letters) followed by a suffix of letters or numbers.

Country prefixes you will encounter include:

Example registrations: OE-CMV, D-EFGH, F-ABCD, HB-CDA. When you use your registration as a callsign, you transmit the entire registration. "Oscar Echo Charlie Mike Victor" for OE-CMV, or "Delta Echo Foxtrot Golf Hotel" for D-EFGH.