My mortgage provider, Chelsea Building Society have the SVR set at 5.85%. They claim that this is acceptable because the majority of their customers invest in savings. The fact that I have a buy to let mortgage with them just makes it even harder to move because the rates elsewhere aren't very favourable either!

Hence as Brooooooooooce states they can choose the rate they want specific to their overall aims.

You answered the the question in your final sentence. Banks are commercial organisations who can set their rates at whatever level they want. I think Woolwich are owned by Barclays, so you would expect their SVR to be similar (although not guaranteed to be).

A quick question re SVR's:

Why is it that some of the "bigger" lenders have far higher SVR's than others? For example, Abbey's SVR is 4.24% but a quick look on the mortgage comparison tool on here shows Woolwich and Barclays (to name but two) are a lot lower. Whilst I don't expect them all to have the same SVR, I would have thought that they would be in the same "ball-park".

I appreciate that lenders are under no pressure to set their rates at anything other than the level they want to, however the difference seems a bit strange to me.