Selling home - not buying another, what happens??

Hi guys

I'm selling my flat but we are not moving into another purchased property - we are going to rent instead as haven't found anywhere just yet.
The initial deal ran out a year ago, am I correct in thinking there shouldn't be an early repayment fee levied? That instead I can just pay off the mortgage at its 'settlement value' (which I know is not the same as the balance you normally see)
Lender is natwest and we are not in negative equity

Thanks guys :)