A319
Flight Crew Air Transport Pilot (ATP)
Communication Breakdown
Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Returned To Clearance
Company Policy; Human Factors
Departing OAK runway 30; contacted NORCAL and was assigned heading 270; climb to 10000. We were then issued a clearance for FL190 and heading 200 or so. I put FL190 in FCU (Flight Control Unit) and acknowledged clearance. Then another aircraft said 'someone else answered for us'. I then reset FCU to 10;000 ft and told PF to turn back to hdg 270. I inquired ATC as to our clearance; ATC responded HDG 270 climb 10;000. PF may not have heard the clearance to 10;000 and hdg 270. I said my aircraft and ensured aircraft turned back to hdg 270 and leveled at 10;000. PM may have not heard 'my aircraft'. We got a 'dual input'; however I re-engaged AP and PF and PM agreed to hdg 270 and 10;000. I then reconfirmed ATC clearance and the PF concurred with clearance of hdg 270 and 10;000. ATC frequency was busy and similar call signs [three ending in XY or YY] all on same freq. ATC then asked the two of us ending XY if we could contact Dispatch and request flight number changes. ATC commented that; 'this happens every morning.'I have noticed many of our flight numbers are within a digit of each other on similar routes and arrival/departure times. We trapped this event and corrected the confusion with the clearance promptly. Avoid using similar flight numbers at same time of day and similar routing.
[Report narrative contained no additional information.]
A319 flight crew reported a heading deviation when they accepted a clearance for another flight with a similar call sign.