The Messerschmitt P.1099 was a 12 m long conventional-looking aircraft with a wingspan of 12.6 m. It had a wider fuselage than the Messerschmitt Me 262 and was equipped with a cockpit for two pilots located at the front end. The planned powerplant were two Junkers Jumo 004turbojet engines, later eventually to be replaced by Heinkel HeS 011 turbojets in a further development with swept wings, the Messerschmitt P.1100. None of the variants were built but this project was developed into the Messerschmitt P.1100 all-weather fighter project which in turn would lead to the single-seat, single-jet Messerschmitt P.1101 design for the Emergency Fighter Program in July 1944.
The Messerschmitt P.1099 project had different versions of double-seat fighters which retained the tail and the wing design of the Me 262. All of the projected aircraft variants would be powered by two Junkers Jumo 004 turbojets.
Jet-powered fighter (Jäger). It had three planned versions with different armaments: Version A with four MK 108 30 mm cannons, Version B with two MK 103 30 mm cannons and Version C with two MK 108 and two MK 103 cannons in the nose.