Flight crew reported a rejected takeoff due to runway incursion.

Attributes
ACN	1667630
Time
Date	201907
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Takeoff
Flight Plan	IFR
Person 1
Function	Pilot Flying First Officer
Qualification	Flight Crew Instrument Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 412
Person 2
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 291
Events
Anomaly	Conflict Ground Conflict Less Severe Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Ground Incursion Runway

Narrative:

We were cleared for departure on runway xxl by tower. The captain lined the aircraft up and passed control of the aircraft to me; the pilot flying. I started advancing the thrust levers up and at the same time I noticed a (other carrier) aircraft; which previously landed on runway xxr; about 3000' or 4000' from us; not holding short of runway xxl as instructed. (Other carrier) aircraft subsequently entered the runway. I still had my hand on the thrust levers. I immediately brought the thrust to idle and gently got on the brakes. We advised ATC that we were rejecting the takeoff due to the (other carrier) aircraft entering the runway. The captain took control of aircraft and I assumed pm [pilot monitoring] duties. We taxied off the runway; ran the appropriate checklists and determined the brakes were not too hot for another departure. The captain spoke with the guests then we departed. This took maybe 10 to 15 minutes. We reviewed our fuel on board and both agreed we were legal for departure.

Original NASA ASRS Text

Title: Flight Crew reported a rejected takeoff due to runway incursion.

Narrative: We were cleared for departure on Runway XXL by Tower. The Captain lined the aircraft up and passed control of the aircraft to me; the Pilot Flying. I started advancing the thrust levers up and at the same time I noticed a (other carrier) aircraft; which previously landed on Runway XXR; about 3000' or 4000' from us; not holding short of Runway XXL as instructed. (Other carrier) aircraft subsequently entered the runway. I still had my hand on the thrust levers. I immediately brought the thrust to idle and gently got on the brakes. We advised ATC that we were rejecting the takeoff due to the (other carrier) aircraft entering the runway. The Captain took control of aircraft and I assumed PM [Pilot Monitoring] duties. We taxied off the runway; ran the appropriate checklists and determined the brakes were not too hot for another departure. The Captain spoke with the guests then we departed. This took maybe 10 to 15 minutes. We reviewed our fuel on board and both agreed we were legal for departure.

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.