Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Last 90 Days 150
Deviation - Speed All Types; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Overcame Equipment Problem; Flight Crew Returned To Clearance
Environment - Non Weather Related; Aircraft; Human Factors
After departing [Runway] XXR from ZZZ [airport] on the ZZZZZX SID; began to accelerate through 9;000 feet MSL using speed mode. This caused the aircraft to level off around 9;300 feet MSL as it was speeding up from 250 KIAS. Captain was talking with ATC regarding our climb clearance when the acceleration began. ATC did not acknowledge the increased speed. After finishing the clearance readback the Captain noticed the increasing speed and changed to vertical speed mode to reduce airspeed. As pilot flying I reduced the thrust as well. Upon reaching 10;000 MSL we resumed normal profile climb.Limited experience taking off with wing and cowl anti-ice on. Normally upon reaching ZZZZZ1 intersection we have reached 10;000 MSL and can begin to accelerate. Because of the reduction in climb performance using the anti-ice system we were 1;000 feet lower than normal.  The use of cowl and wing and anti-ice also caused the aircraft to use a lower angle of attack to reach entered airspeed resulting in a reduced climb performance. Because of reduced loads from COVID-19 we have normally not encountered a problem reaching 10;000 MSL before the west bound turn resulting in a habit of increasing speed at ZZZZZ1 or west/east bound turn.
Air carrier First Officer reported exceeding 250 knots below 10;000 feet due to a reduced passenger load on climbout.