We analyzed strong magnetic storm and sub-storm influence on the GPS operating in the Arctic region. 5-years dynamic were analyzed based on IGS and CHAIN data (∼ 200 receivers at more than 55◦ N latitude). The main studied parameters were phase and pseudorange slips as well as sharp physically unrealistic total electron (TEC) values variations (TEC slips). TEC slips were found to increase 100–200 times higher than just instrumental noses under helio- geomagnetic disturbances of different nature. The major cause of phase and pseudorange slips is GPS signal absorption in the ionosphere. The absorption is caused by high-energy particle precipitation during magnetic storms at high latitude.