Air carrier first officer reported taking a clearance intended for a similar sounding call sign airc...

Attributes
ACN	1644392
Time
Date	201905
Place
Locale Reference	LAX.Airport
State Reference	CA
Environment
Light	Daylight
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Climb
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	Climb
Flight Plan	None
Person 1
Function	Pilot Flying First Officer
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 516
Events
Anomaly	ATC Issue All Types Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Deviation - Track / Heading All Types

Narrative:

Our call sign was xxyy and xyy was on the same frequency headed in the same direction. Xyy was given direct brkkk and we read it back and accepted the clearance. After our climb and direct too; ATC advised we had taken flight xyy's clearance.

Original NASA ASRS Text

Title: Air carrier First Officer reported taking a clearance intended for a similar sounding call sign aircraft.

Narrative: Our call sign was XXYY and XYY was on the same frequency headed in the same direction. XYY was given direct BRKKK and we read it back and accepted the clearance. After our climb and direct too; ATC advised we had taken Flight XYY's clearance.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Air carrier first officer reported taking a clearance intended for a similar sounding call sign aircraft.