In the early 90's I ran into difficulties paying the Bradford & Bingley mortgage on my studio flat. At this stage I had been letting my flat for some years without the knowledge or permission of the building society. I was called in to the local branch to discuss the arrears and the manager advised me verbally to start letting a room. He stressed he was doing this 'off the record' and that, officially, he was not saying anything. I assume this was to get around Head Office restrictions. I was grateful for this attitude and continued to let my flat with the unofficial consent of the local manager. A short while later I caught up with the payments and have had no further trouble.(posted 8918 days ago)If you request permission to let I doubt they would forclose. They are more likely to a) send you their own tenancy agreement form for you to use b) charge a one-off fee. c) possibly raise the interest rate on your mortgage by half a percent