Should I be concerned about this crack

[Dazedandconfused170]

This crack has been here for a while, but only recently noticed it was this bad. the house has a few cracks but nothing as big as this. These pictures are taken 3 weeks apart and it’s got slightly worse - what do I do?
is filler enough or do I need to call someone?
If so, who exactly do I call?

It’s next to a bay window, there is also a crack on the other side of the window but nowhere near as bad 😣

Any help appreciated!

A diagonal crack can be indicative of movement.

Is there a crack on the outside wall? It could be a sign of subsidence, but it could also be a thermal shift, which would not be concerning.

I’d keep an eye and consider getting a structural engineer to survey it if it gets worse.

If it's just internal I wouldn't be too worried. It just looks like normal old house movement.

thanks for replying. I’m unsure about the outside as it’s a bedroom wall but will try and have a look
Do you know if it’s likely to be costly to get a structural engineer out?

Your home insurance would pay. But I’d not worry until you’re sure it’s worsening.

Bay windows sometimes move away from the wall they are attached to as the weight of the bay pulls them downwards leading to cracks.
That is what I would suspect if nothing else is moving
Wouldn’t panic see how it goes. You could get a structural engineer price varies about £500 ish though usually