Can someone explain Split Mortgage arrangement

as it says on the tin - can someone explain how 'split mortgage' works ? PLEASE !

It may not even be an option for us - we are looking at a shortfall due after the disposal of BTL property. But I don't understand how it works.

Thanks in advance

You should complete the following:

Information required for mortgage arrears and negative equity questions

Back in the day I had a split mortgage. At the time my mortgage was for €100k. I took out a fixed rate mortgage for €40k and a variable rate mortgage for €60k. Both at different rates but both over a 20 year loan termwith the fixed rate for 5 years . I was able to make lump sum repayments off my variable rate portion.

That is why you should complete the full data. You presumably are not asking about what Grizzly has answered?