Make sure the compass is flat when using it.
Your compass must be flat to detect the magnetic north correctly. Place your compass in the palm of your hand. When using a map, place the compass on the map on a flat surface.
If your compass is not detecting the north
Use your compass at sufficient distance from any magnetic sources which will affect its capacity to detect the north: high-voltage power lines, mobile phones, keys, metal objects, and even another compass can affect the direction.