Flight Crew Last 90 Days 232; Flight Crew Type 9075
Communication Breakdown; Confusion; Situational Awareness
ATC Issue All Types; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification
Aircraft; Company Policy
Our call sign was Air Carrier XYXX. Approximately one hour into the flight at cruise altitude; both the Captain and the First Officer heard ATC clear us to descend to 35;000 feet. The Captain repeated the clearance to ATC and the First Officer set 35;000 feet into the mode control panel and confirmed the new altitude with the Captain before starting the descent. As the aircraft descended through 35;300 feet ATC told us that we had accepted a clearance intended for Air Carrier XXXX and told us to climb back to 36;000 feet. ATC then told us that Air Carrier XXXX was on frequency and had a similar sounding call sign. The rest of the flight and landing was uneventful.
[Report narrative contained no additional information.]
Air carrier flight crew reported taking a clearance intended for a different aircraft with a similar sounding callsign.