Maximise Interest on Spare Money - Tips Wanted!

Hello all, new to the forum and looking for some advice.

I have roughly £40k to my name currently and am wondering how to maximise the amount of interest I can earn on it. I have £20k (the limit) ticking over in a Santander 123 account, so that is earning 3% interest i.e. paying me around £50 a month.

Can I do better than just shoving the remaining funds in another savings account? After a quick glance around I can't seem to find anything that would pay much more than 1%. I would also like to have access to the money at all times with no penalties ideally, so that I can buy a house when the right one comes up.

Just wondering what others typically do and if I can do anything better than I am doing currently?

Thanks in advance!