Inform bank of letting house?

I am looking for some advice please. We have become very reluctant landlords. We have two houses one of which is our principal residence and another house which we owned and used to live in before moving into our principal residence we have now rented out this property.This is our first year renting out this property.

We receive the TRS on our principal residence and we have the tennancy agreement on the other house registered with the PRTB.

However we have not informed the bank that the house is now rented.We have been on a fixed interest rate of 5.25% on the house which is now rented this is due to end shortly and I wonder should we now tell the bank that the house is rented or any other advises on the above situation would be greatly appreciated.

Hi Worry

This is discussed at some lenght in other threads on askaboutmoney

Do a search - maybe the Property Investment forum?

Thank you will have a look there.