cracks in house walls

[boogiebabe]

when we took wallpaper off last summer we found cracks near the ceiling. When we went outside we found similar cracks in the outside wall running down and to the right, following the bricks. We have kept an eye on them and they do not seem to have got any longer or wider. Inside the biggest one is about 18" and outside about 3'. We are very worried about them, when do we tell our insurance company. It is a 1930's semi detached bungalow and there isn't any subsidence in the area. Any advice would be welcome. Thank you.